He and his wife, WWE Diva AJ Lee, were on hand in UFC 181 when he made his announcement.
He is entering the promotion with a 0-0 professional record just like his predecessor Brock Lesnar, who eventually became the UFC Heavyweight Champion before returning to WWE.
In an interview with Ariel Helwani for FOX Sports, Helwani asked Punk what his response is to naysayers who say he's a fake wrestler who doesn't know how to really fight. His response is, "If that's your opinion, that's awesome; it's my job to change your mind."
I won't wish him good luck, because luck is for losers.