Play as Tigatron:
To play as Tigatron, go to any mode which allows you to choose a character. Highlight Cheetor, press and hold Z, and press A. Then, when they allow you to switch his color, press Right on the analog tick a couple of times, and you will se Tigatron.

Play as Blackarachnia:
To play as Blackarachnia, go to any mode which allows you to select a character. Highlight Tarantulas, press and hold Z, then press A. When they allow you to choose the color, flick the analog stick right a couple of times and you will she Blackarachnia.

Play as Decepticon Starscream:
To play as Starscream, go to any mode which allows you to select a character. Highlight Waspinator, press and hold Z, then press A. When they allow you to choose the color, flick the analog stick right a couple of times and you will see Starscream.

Play as Basic Rattrap:
To play as the Basic Rattrap (the mouse and not the mechanical robot kind)go to any mode which allows you to select a character. Select Rattrap by pressing A. When they allow you to choose the color, flick the analog stick right a couple of times and you will see the Basic Rattrap. Note: They will not change the name, so you will have to see it yourself.

Thanks to Revolution reader Gamer!