Butch
Hold L and press X, R, A, X, R(2).
Peelgood
Hold Down/Left, then press B, Y(2), A, Y.
Sarge
Hold X, then press L(2), Up, Down, Left, Down.
Jack
Hold Up, and press A(2), R(2), Y, A.
Ice
Hold B, and press Up, L(3), Right.
Thunder
Hold Up/Left, and press Y, B, X, B(2), X, A.
Slyck
Hold Y, and press L(2), Up, L, Left, R.
Spike
Hold R, and press X, B(2), A, Y, Left, A.