Naked Penguin/Prinny (whatever floats your boat)aka Big Dude. Solid Penguin/Prinny Liquid Penguin/Prinny Solidus Penguin/Prinny. The 3 Sons.
I can go on for the whole cast if I wanted. Example Revolver Kitty/Saber Kitty (whatever one u like) MGS4 version Liguid Kitty/Saber Kitty since Ocelot is a cat, or I wouldve used Gunner but Revolver Gunner sounds stupid Liquid Gunner not so much.