Not that I know of. The only way you can kill enemies with froggy is using sugar rush.

EDIT:

There's actually another way, but it's a bit more complicated.

You could put ammo MCEs into crates, get the crates to break somehow and the ammo coming out would kill the enemy.

I guess you don't know how to even create MCEs though (not meant as an attack), so you'd need to learn how to do that first.