I had a player choose to be "Vegeta, Prince of All Saiyans, from outer space" in Curse of Strahd. I was DM and had never banned a player before, and didn't start then. The other players begged me afterwards to toss out any player that pulls something like that immediately. Or at least make them pick something appropriate.

On joke characters I've played beside, I've run into several that have irritated me, but it's not universal. It comes down to a simple question: are they legitimately funny? If you're playing a one off you might be able to get away with a bizarre reference or lukewarm joke name that elicits groans from the table, that name only has to be repeated maybe a dozen times. Now imagine a long campaign, the sort of game every player and DM really hopes to land in. One where your joke has to be repeated every week for months, or even years. Take a moment and seriously think; is it still going to be funny?

Ask a cashier what they think when an item fails to scan and the customer says "haw haw, must be free!". Look them in the eyes. See the burning hate. That is your bad one note joke character spread across a campaign. Save it for a one shot if you must.