smutny
Airman
Venom and Viper are the US Marine versions of upgraded H-1's.
Cobra is really the only standout in official Army names.
Defender is the manufacturer's marketing name of the H-6 while Little Bird is the nickname of the A/MH-6.
Most airframes get nicknames from their crews over time.
F-16 - Viper
A-10 - Warthog, Bionic Turtle
B-52 - BUFF
A-7 - SLUF
B-1 - Bone
F-4 - Double Ugly, Rhino, Smokey
etc.. etc...