That first depiction of Jesus, "Alexameno's Graffito" is interesting af. I read a little about it, and it seems like it was engraved in a boarding school that got walled off for centuries.

In one room, somebody inscribed "Alexameno is faithful," or something to that effect. Then, in a different room, somebody drew Jesus with the head of a donkey being crucified, and a worshipper venerating him. Underneath is written, "Alexameno worships his god." This could've been to make fun of the other kid who wrote the first graffiti. I just thought that was super interesting.