(It looks like this post is about question posts specifically rather than answer posts.)
Quora has a specific report reason for joke/troll answers. I cannot believe that Stack Exchange which even removes 'thanks' and is of course generally far more strict than Quora (which in some ways is kind of like Yahoo Answers anyway) allows this. Does Stack Exchange lack such a policy that applies to every site? Is it really up to each site to decide whether or not to allow joke/troll answers?
Btw, there may be another law involved. See here:
Ah, but the problem here is rather Poe's Law. Even if the joke is outrageous, some simply won't get it. I'm taking bets pkr's answer above falls under it. Thus, whereas I might put in puns, popcultural snippets and anecdotes into my answers, I'd avoid outright joking. – Hauke Reddmann Feb 20 '21