Definitions by ▒☺♫

Sly puppy 

A person who is just beggining to be sneaky,devious,lucky,slippery, etc. and will eventually be a "sly dog".

Gabe: That new kid is trying to steal Austin's wallet.
Channy: He is such a sly puppy.

Sly puppy by ▒☺♫ May 6, 2009