When a well endowed man drops his hard erect penis on the face or forehead of one of his buddies while several people are present to laugh at the act. The ultimate Tomahawk Kawk Drop is performed when the penis is rather dirty and seemingly has the smell of salt and vinegar.
Boomer: Dude you were so wasted at that party last night!!! Do you remember doing a TOMAHAWK KAWK DROP on Zach's forehead?!?!?! That shit was so funny!!!
Tom: Yeah...I was drinking non-alcoholic beer. I was aware of exactly what I was doing!