Nurse!

File Under: "You Know You're In Trouble When" ... you punch a guy in the face as hard as you can -- AND HE DOESN'T GO DOWN ... because the guy you punched is a UFC fighter.

That's exactly what happened in Vegas -- when 27-year-old UFC star Cody "The Renegade" Gibson (12-5) got into a standoff with some dude with a death wish at a bar in Downtown Las Vegas.

It all went down last week ... after Cody's last-second defeat at UFC 178 to Manny Gamburyan. Despite the loss, Cody still felt like going out ... and that's when he got into it with another bar patron.

Sources at the bar tell us ... the two guys got into an arguing match that escalated quickly -- but when it almost came time to fight ... Cody tried to WARN the guy he's a professional brawler.

In the video, you can actually hear Cody tell the other man "Google me, bitch!"

But the other guy didn't listen ... and instead of googling, he SOCKED CODY IN THE FACE.

Cody was stunned ... but didn't go down ... and responded by tackling the guy to the ground.

Security quickly rushed in ... but no one was arrested or seriously injured ... which is good for the dude in the blue shirt, considering Cody is constantly training in Brazilian jiu-jitsu, boxing and Muay Thai fighting.

Bottom line -- props to Cody for not killing the guy.

Amanda Bynes puffed a Camel cigarette on the streets of NYC Friday evening ... then rolled into the Cartier store wearing sweatpants ... and the situation continues to be desperate with no happy resolution.

Bynes -- sporting a bandage under her eye -- walked around the Upper East Side Friday before hitting up the fancy jewelry store.

Doesn't look like she bought anything ... as she left the store, undercover.

We spoke with multiple people who saw Amanda in Union Square last night as well ... and they say she seemed very paranoid. They also tell us she was speaking to inanimate objects like a tree.

Amanda Bynes landed in New York City Friday morning with a large Band-Aid across her face.

Bynes was walking through the airport, fussing with her freshly dyed hair with a sweatshirt tied around her waist. The strangest part of her appearance was the huge bandage under her right eye ... covering most of her cheek.

As TMZ first reported, Bynes was spotted at LAX before her Thursday night flight and she was acting very strange. Unclear if she had the bandage in L.A.

People close to Amanda are saying ... before they can take action to get her help, she has to pose a danger to herself or others. It's possible this is a sign of that.

Amanda Bynes is off to NYC ... and she is not well.

Amanda was at LAX Thursday night at an airport restaurant, acting bizarre, painting her face with excessive amounts of makeup.

Sources connected to Amanda tell us she was visibly high all day, talking to herself and complaining about her life.

The pics below are from a Thousand Oaks, CA hair salon, where Amanda got a dye job. She was there for several hours -- again acting bizarre -- before heading to the airport.

We believe she is now in NYC.

"Evel Dick" Donato says a romp with a Vegas stripper is why he's HIV positive ... so he thinks.

Dick tells TMZ ... he had unprotected sex with the stripper -- who he says got her period during intercourse. Dick says, "When I woke up, she was gone and I looked like I had murdered someone."

Donato was diagnosed in 2011 ... from blood tests administered on "Big Brother." Donato says he left the show and broke the news to his mother and his girlfriend ... calling it the "hardest conversation I have ever had to have."

Dick says his GF -- who tested negative -- was amazing ... assuring him they would get through it. She stuck by him for the next two years, until they split in 2013. They're appearing on "Couples Therapy" to see if they can re-ignite their relationship.

Dallas Mavericks owner Mark Cuban tells TMZ Sports ... he's not worried about the Ebola scare in Texas ... but he's instructed his players to NOT travel to Africa for the time being.

Cuban also says he's instructed his players -- who habitually visit sick people in local hospitals -- to not make an in-person visit with the Ebola patient who's being treated in Dallas ... for obvious reasons.

Charlie Sheen admits he went crazy in a dentist's chair last week ... but insists he was NOT on drugs -- he had a horrible reaction to nitrous oxide ... and the technician who is making the allegation is just bitter because she was fired for violating the law.

Charlie's rep, Jeff Ballard, tells TMZ ... Charlie was on meds for a shoulder injury and the combo of the Rx he was on along with the nitrous caused the reaction. We're told Charlie's arms did flail and he accidentally knocked over the dental instruments on the tray, but that was it.

Furthermore ... Charlie's lawyer, Marty Singer, tells TMZ, "The story is being made up by this woman [the dental technician] who was fired on Friday for violating HIPAA by telling her son Charlie was in the office. It got back to Charlie and the dentist fired her."

As we reported ... the technician told cops the dentist told her Charlie came at him with a knife and his bodyguard said he was on rock cocaine.

But law enforcement sources tell TMZ ... the dentist was interviewed Thursday and was clear with cops ... the technician was LYING. There was no mention of drugs and NO KNIFE.

NY Giants co-owner Steve Tisch is clearly not worried about the Ebola scare in Dallas -- telling us the G-Men have nothing to worry about when they head to Big D to play the Cowboys later this season.

Tisch was leaving Dan Tana's restaurant in West Hollywood last night when we brought up the efforts to contain the virus after officials confirmed that it had reached Dallas.

"I think the Cowboys are gonna get it first," Tisch joked ... clearly not worried about a possible "Outbreak" style epidemic.

Tisch then started down a path to crack a joke about Jerry Jones ... but stopped himself.

So we finished it.

Charlie's lawyer Marty Singer calls the allegations "completely fabricated." He adds, "No bodyguard made the absurd statement to the dentist. Charlie had a bad reaction to the noxious gas put in his mouth and nose."

Charlie Sheen clearly doesn't like going to the dentist, because he's under investigation for assault with a deadly weapon for allegedly going nuts in a dental chair in a rock cocaine-fueled rage ... TMZ has learned.

Law enforcement sources tell us ... Charlie was at an L.A. dental office last Thursday for an abscess. He sat in the chair as the dental technician placed a mask over his face to administer nitrous oxide, when she says Charlie went insane ... flailing his arms and striking her.

The technician told cops she walked out of the room as Charlie's security guard entered. Charlie's personal dentist was there along with the oral surgeon. There was a lot of commotion and the technician says when Charlie's dentist finally came out he told her Charlie pulled a knife and went after him. The dentist wasn't hurt.

The technician also told cops the bodyguard told the dentist Charlie was high on rock cocaine.

We're told there's an active LAPD investigation and cops are looking at a possible battery against the technician and felony assault with a deadly weapon for the alleged knife attack on the dentist.

We're told cops want to interview Charlie and the dentist before sending the case over to the L.A. County D.A., who will decide whether to prosecute.

We reached out to Charlie ... so far, nothing back.

The little girl who stopped an Ebola outbreak 20 years ago -- in the movies, anyway -- is right in the middle of the real life outbreak in Dallas ... and she's terrified it can't be blocked this time.

Kara Bosworth played the hero kid in "Outbreak" back in '95. She's the one who captured patient zero -- the African monkey that brought Ebola to the U.S. -- and as bad luck would have it ... she now lives in Dallas.

Kara tells us she's keeping a close eye on the case everyone's talking about, but doesn't plan on fleeing Big D ... yet. Kara, now 25, learned a few things from the movie ... telling us she won't run for the hills unless the virus mutates and becomes airborne.

Tracy Morgan was seen Wednesday afternoon being wheeled into a New York City hospital ... and TMZ has learned he might not be ditching the chair anytime soon.

Morgan is still recovering from the horrific car crash back in June when a Walmart truck collided with his van. Sources close to Tracy tell TMZ ... Morgan's injuries stemming from that crash may prevent him from ever walking again without some kind of assistance.

Morgan has been feuding publicly with Walmart after it claimed in legal docs his injuries were due in part to the fact he wasn't wearing his seat belt.

Morgan responded by saying, "My friends and I were doing nothing wrong."

One of "Evel Dick" Donato's former "Big Brother" housemates tells TMZ ... she wishes Dick would have STAYED in the BB house after learning he was HIV positive -- but Dick says he didn't have a choice.

Donato -- who won BB in 2007 and then rejoined the cast in 2011 -- left the show very early into Season 13 when he was informed by producers that blood tests showed he had HIV.

We spoke with Rachel Reilly -- who was competing in the house at the time -- who tells us she wishes Donato would have stayed in the game.

"If he had a meeting with everyone it would have been a way to give the disease a voice," Reilly said ... "It's reality TV."

She adds, "I think it's cool he is talking about it 3 years later and I hope this changes people's lives. I think it's brave of him."

We also spoke with Evel Dick on "TMZ Live" moments ago ... who told us he didn't get a choice to stay in the game -- producers told him he had to leave.

But he also says he wasn't ready to go public with the information anyway ... "This was the most shocking news I've ever been told. I needed time to digest."

Donato says it's already destroyed him in one way -- financially.

For their part, a rep for CBS tells TMZ Dick was not forced to leave the show, but rather made the decision on his own.

Amanda Bynes was under the influence of Adderall when she was arrested for DUI ... sources familiar with the situation tell TMZ ... but her problems go much deeper than a criminal case.

We've learned the Adderall was prescribed by a doctor and she had taken the drug before getting stopped in Van Nuys Sunday and failing multiple field sobriety tests. She was arrested for DUI.

Adderall is a stimulant and we're told Amanda was "out of it" when she was stopped.

Fact is ... it's no defense to DUI that the drug in question was prescribed -- it's still operating a vehicle while impaired. But Amanda now faces a probation violation -- she's on probation for reckless driving -- and the fact that the drug was prescribed may help her there.

The deeper problem is this ... As TMZ first reported, Amanda has moved out of her parents house and is now living in Orange County. We're told she's smoking a lot of weed and is off her anti-psychotic meds for Schizophrenia and bipolarity.

Amanda's conservatorship ended earlier this month and we're told her parents saw no need to extend it because they believe she's better now, but everyone else in her life feels it was a horrible mistake to let the conservatorship lapse and they fear for Amanda.

Rich Homie Quan's father got shot multiple times this morning, and the rapper is by his side in an Atlanta hospital ... TMZ has learned.

Quan's dad, Corey Lamar, was in the barber shop he owns this morning when a man ... or men ... came in and attempted to rob the place -- and during the hold up they opened fire ... according to Quan's rep.

We're told Lamar -- who is Quan's manager -- was hit 4 times. He was rushed to a hospital and taken into surgery. We're told he is in critical condition, but expected to survive.

RHQ was at the hospital when his father got out of surgery. Police are investigating the shooting. So far, they know the suspect fled the barber shop in a black Honda.

Michael Ian Black NAILED a guy on a scooter Sunday afternoon.

It went down at 3:00 PM Sunday at the very congested corner of Highland and Santa Monica Blvd. Black's Toyota struck the scooter ... sending the rider tumbling to the ground.

We're told the scooter driver suffered road rash on his left leg. An ambulance showed up ... but apparently it wasn't serious enough ... the scooter driver was not transported.

Black was not ticketed. Accidents happen.

We reached out to Black for comment ... so far, no word back.

At least three people were killed during a monster truck event in the Netherlands Sunday when a driver lost control of his vehicle and plowed into a crowd of people.

The monster truck had just completed routine trick -- where it drives over several parked cars -- when it veered left, taking out a guard rail and dozens of spectators who were standing behind it.

The mayor of the town where the event took place told media that 3 people were killed -- including one child -- and 15 other people were injured.

One of the event organizers told local news he believes the problem could have stemmed from one of two things -- either the gas pedal got stuck or the brakes failed.

The driver is reportedly being questioned by police.