Puncha yo Buns

This is a song sung by Baby Finn in "Memory of a Memory." While in Finn's mind, Marceline witnesses a memory of Baby Finn singing this song in the bathroom of Finn's childhood home.

Lyrics
I'm a buff baby,

That can dance like a man.

I can shake-a my fanny,

I can shake-a my can.

I'm a tough, tootin' baby,

I can punch-ah your buns.

Punch-ah your buns,

I can punch all your buns.

If you're an evil witch,

I will punch you for fun!

Trivia

Baby Finn doesn't fart at the end, it is a spurt of laughing by Marceline.