Just picked some up at Dollar General:
A14125MM - Donnie
A16125MM - Raph
A17125MM - Mikey
A18125MM - Shredder
A19125MM - Kraang
A21125MM - Foot Soldier
So I'm guessing A15 is Leo and A20 is the Foot Bot. Heading back in a few as I bought multiple A16 thinking THEY were the Foot Bot (from one of the YouTube videos)!!
EDIT!
A15125MM - Leo
They didn't have any other numbers other than what I have listed, and they didn't have any other Kraang/Foot Soldiers either! I was going to pick up one more of each Kraang and Foot Soldier, and then a Foot Bot if they had it. Luckily I was able to exchange my unopened A16 Raph for A15 Leo

