TMZ Live

Kevin O'Leary is in a pretty good mood, considering he and the other "Shark Tank" moguls missed out on a cut of $1 BILLION Amazon paid for a product they let slip through their hands.

Mr. Wonderful talked to us about whiffing on Ring, a smart doorbell company once pitched on "Shark Tank" (as DoorBot) by its creator Jamie Siminoff. Kevin proudly reminded us he's the only shark who made an offer.

Even though he couldn't close the deal, Kev has no hard feelings and says he KNEW Jamie was gonna make it big.

Now that Siminoff's a billionaire, Mr. Wonderful has some advice for him on what to do with his cheddar. Hint: It's time to swim with the sharks.

Offset gets the award for best "plus one" ... after pulling a last minute surprise at a "Black Panther" screening for at-risk kids, and not even the event organizer knew he was doing it.

Jas Waters, a writer on "This Is Us," told us how she came up with the idea to screen the film at the El Capitan Theatre in Hollywood over the weekend. It all started with her offering 2 free movie tickets on Twitter ... and ended with Offset marching into the screening with Lil Yachty.

As we previously reported, several celebs have been participating in the 'Black Panther Challenge', where they help disadvantaged and minority children see the film for free.

Nikolas Cruz, the now-confessed Florida school shooter, was on the FBI's radar 5 months ago, thanks to a man who reported a disturbingly violent comment Cruz left on a YouTube video.

We spoke to Ben Bennight, a Mississippi bail bondsman, who says he regularly posts vids related to his job. He says back in September he noticed Cruz commented on one of them, saying ... "I'm going to be a professional school shooter." He says he immediately contacted authorities.

Ben told us all the details about his FBI interview, and added ... he never heard from agents again until after Wednesday's horrifying events. Cruz now admits to killing 17 people during the rampage at his old high school.

The FBI says it never made contact with Cruz after they spoke to Ben. They say the comment was not specific enough to warrant a subpoena for an IP address or other info from YouTube ... which might have led them to Cruz.