This will be your current alien forms. New ones will be unlocked later on. Here they are.
Heatblast
Feedback
Four-arms
Spidermonkey
Big Chill
Kicken-hawk
Way big
Diamond Head
Blitzwolfer
XLR8
Armodrillo
Swampfire
Humungousar
Chromastone
Grey Matter
Jetray
Water-Hazard
Crashopper
Echo-Echo
Ripjaws
You have 20 aliens since the Omnitrix is the most advance one. I'm also gonna put some ultimate forms. You guys suggest the aliens you want so that I can out it here. Thanks in advance. PEACE. XD