The "Never Ending Pie Song" is a song Finn sings in the episode "What is Life?" while he builds Neptr, a robot designed to throw pies and prank Jake. The lyrics are describing how Finn thought he would prank Jake.
| I'm gonna build me a pie throwin' robot|
That throws never ending piii-ies
On Jake's ugly faaa-ace
| And he won't know what hit him|
'Cause the pies are