Bobby was visiting a friend and given some coffee that he was not informed was spiked with a youth potion, which reverted him back to being a baby.. He doesn't look too pleased with this, but thankfully, it's only for an hour or so.

"And if any of you tells Dipper, you're gonna get it."

Lineart by Victor, and colored by nelson88 of Inkbunny who has the picture posted here

Note: I got this picture for winning an art raffle.