I think the response is an edit, in the original Raph stays quiet.
A, kinda ironically for this post, this whole scene happens because Raphael is against Turtles teaming up with Batman because he thinks Batman is a rich guy who fights crime as a hobby and doesn't take it seriously and Batman JUST COULDN'T THINK OF A BETTER WAY TO CHANGE HIS MIND!
Assuming Batman is another PC, it could be that player overestimating. And also being as uncreative af because Batman's backstory is a standard part of the Junior Edgelord Unhappy Meal character design package.
I have the exact opposite problem-- all of my characters are 'serious campaign' characters, I'm physically incapable of writing bit, joke, or gag characters. Everything new I draft up's gotta fit in with the rest of my rogue's gallery.
I had a problem similar to this in the beginning, but being given a chance to play one-off characters (for one-shots and the like) gave me the chance to experiment and lighten up. Most of my one-shot characters ended up being parodies of their models—either playing them as a joke contrasting with their tragic backstories or giving a more tragic twist to their relatively joke-y backstories.
Not sure if it's at all relevant here, but this reminded me of a character for a one-shot (more like a side-story to a long-running campaign) that I made. He had a pretty serious and "edgy" backstory: his parents died when he was very young and was taken in by his grandfather. After the grandfather died, he was passed off along several relatives until he found himself in an orphanage, where he eventually became too old for it, and went on to be an adventurer.
However, the character was modeled on Pico of Boku no Pico (and its other sequels). I gave him polearm mastery (because, long and pointy things), and I wanted him to carry a "pike" but for more practical reasons, I just gave him a halberd. Continuing on with the extended joke of a character, I have him have a height of over 6 feet, and a bulky, well-built body (out of a lifetime of manual labor, ofc). And to top it all off, I played him as a sweet innocent boy, liking ice cream and being huggy and an overall bundle of joy to be around.
Not everyone in the table got the joke, but the look of the faces of those who knew, priceless! It did play quite decently though, which is a huge bonus.
Well, what can I say? I'm as cringe as you say I am. Tell me more about myself.
The joke was that for those who knew about it, it's downright disgusting, as you've very graciously pointed out. Also, the pike is an attempt at a pun. I actually didn't think of it being phallic until you pointed it out, so, thanks!