Comedy Central

File this under "Things You Didn't Expect to Hear Today" -- Wayne Brady is under fire for a RACY joke he made at the "Comedy Central Roast of Roseanne" .... WAYNE BRADY!!!

So what subject was so touchy that the crowd actually booed?? Brady made a joke featuring Sarah Palin's son Trig ... who suffers from Down Syndrome.

Now for the joke ... which Brady made while addressing Jeff Ross:

"Now the thing is Jeff ... these are all jokes, and I really like you. I really, really like you. But a lot of people hate you, especially Sarah Palin because you remind her of what Trig is going to look like when he’s 40."

After years of HATING EACH OTHER'S GUTS -- Tom Arnold says he made a last minute appearance at Comedy Central's roast of Roseanne last weekend ... to bury the hatchet once and for all.

TMZ broke the story ... A few weeks ago Tom was adamant he wanted nothing to do with the CC bash ... not surprising since he and Rosey had a notoriously nasty split back in 1994.

But a producer for the show tells TMZ ... Tom initially turned down his invitation to participate in the "Roast" ... but had a change of heart at the very last second and contacted producers to let them know he changed his mind.

We're told producers were on board, but had to get the green light from Roseanne first ... and in another shocking turn of events, she said yes.

The best part ... we're told after Tom roasted her, the pair shared a private moment backstage for the FIRST TIME IN 17 YEARS.

In case you're curious, here's one of Tom's "jokes" that helped settle their long-time beef:

"She may not be the perfect wife, but she is literally the worst f-ing EX-WIFE on the planet ... trust me."

Comedy Central is censoring Jeff Ross ... refusing to air the jokes he made about the "Dark Knight Rises" massacre during this weekend's taping of the "Comedy Central Roast of Roseanne."

Ross -- who came to the event dressed like Joe Paterno, accompanied by two young topless boys -- has been under fire for cracking the following zinger, directed at Seth Green:

“Seth, congratulations. This is actually a great night for you ... you haven’t gotten this much attention since you shot all those people in Aurora. ... I’m kidding. You are not like James Holmes. At least he did something in a movie theater that people remember!”

Comedian Jeffrey Ross made quite an entrance to the Comedy Central Roast of Roseanne Barr last night ... dressing up as legendary Penn State football coach Joe Paterno and walking the red carpet with two very young looking males wearing nothing but towels.

Don't count on hearing any awkward jokes about having sex with Roseanne Barr -- because her famous ex-husband Tom Arnold wants nothing whatsoever to do with her upcoming Comedy Central roast.

A rep for Tom tells TMZ, the actor will NOT be reaching out to Comedy Central to participate and will say no if the network reaches out to him.

The rep adds, "He has absolutely no interest in being apart of it." The rep explained the couple simply doesn't talk anymore, and that's not gonna change any time soon.

Tom and Roseanne were married from 1990-1994 -- and their split was notoriously nasty, culminating in a screaming match outside the "Roseanne" set in 1994.

Cocaine ... hangovers ... and mug shots -- Mike Tyson and Charlie Sheen are a match made in Comedy Central Roast heaven ... and TMZ has learned Iron Mike is officially on board to skewer the Warlock next month.

Sources heavily involved with the Roast tell us ... Mike will be on the dais on September 10 ... along with Steve-O from "Jackass" ... comic Anthony Jeselnik and Roast legend Jeff Ross.

Lisa tells us, "I am personally thrilled to death that they chose Charlie and I'm glad he's desperate enough to have accepted the challenge. I mean, come on -- the guy was replaced by Ashton Kutcher. I guess he now knows how Bruce Willis felt!"

But she adds, "Sadly, I'm actually booked to do a show that night already, but if there's any way I can get out of it, all I can say is, "Charlie, here I come!'"

The show is scheduled to tape September 10 in L.A.

Sheen released a statement saying, "You could say I've been providing kindling for this Roast for a while ... It's time to light it up.& It's going to be epic."

The Roast will be taped in Los Angeles on September 10 ... and it will air on Comedy Central on September 19 -- which is, not coincidentally, the same night the revamped "Two and a Half Men" is set to premiere.

A rep for Comedy Central says, "Charlie has assured us that nothing will be off limits in this Roast which scares even us."

Story developing ...

During a burger run in L.A. last night, Martling told us that Howard loves radio so much, he'll be doing it "until the day that he dies."

Both Greg Giraldo and Joan herself made the jokes -- but they leave us with just one question ...

There's a reason insult master Lisa Lampanelli didn't show up to the Comedy Central roast of Joan Rivers this weekend -- if she couldn't be in charge, it wasn't worth her precious time.

A week after Kathy Griffin was announced as the roastmaster for the event in Los Angeles, Lampanelli -- who's usually the headliner at these things -- dropped the following message on her Twitter page:

"No Joan Rivers roast for me this year. Not worth doing if I ain't roastmaster -- besides summer is for fun, not work."

Perry Caravello, the one-time "star" of a practical joke flick, filed suit today in Los Angeles County Superior Court claiming, among other things, the three funnymen owe him $10.5 million.

For several years, Caravello was duped into believing he was going to play the lead role in the faux action flick "Windy City Heat." Every actor and member of the crew was in on the joke -- except Caravello. The final product, er, joke, aired in 2003 on Comedy Central.

In his suit, Caravello claims the defendants "falsely and fraudulently" represented the project, and promised him, among other things, that he "would be paid 10 million dollars if he placed his penis in a mousetrap." Caravello says he "was severely injured when the trap literally went on his manhood." Ouch. To add insult to injury, Caravello says he's suffered "humiliation and emotional trauma" because the video has circulated the Internet. Talk about viral.

Caravello is suing for the $10.5 million that he says he is owed, plus damages and medical expenses.