Ant
Walks on walls and ceilings.
Bear
Slow, but tanky. Can dig through bedrock.
Chameleon
Becomes invisible when standing still.
Mole
Deploys an automated turret.
Platypus
Swims like a torpedo and holds its breath for a full minute.
Spider
Slings a rope to swing across the map, and weaves a web that slows down enemies.
Viper
A glass cannon. Double the reach and damage.