Can someone tell me the name of the book where the frog eats the butterfly in the end?

[BroccoliSpears]

...or something along those lines.

They're best friends and they agree to be best friends for ever and then one eats the other.

??

Dd has it, can't remeber the name it's about a tadpole and Caterpillar.

Tadpole's Promise

Tadpole's Promise by Jeanne willis and Tony Ross

I love that book

Thank you!!