Agent K's Theme is a song from the episode "Agents Against Teacher" from Kirby Quest as from the credits.
He's a cute little agent pullball who slies.
He is a tiny little hero and he's always on the run!
The cute's not always cute. He is a villain killing machine.
And when he's here you can hear the villains say
Mr Crocker: Oh drat! Now I have this song stuck in my head!
He's Kirby, Kirby the puffball!
He's Kirby, Agent K!