A lot of the characters in Bighead are based on friends. Here's a short comic with Bigshot, based on my pen pal of sorts Kav. Bigshot's hands explode at criminals. The Grenade Jumper was something that came up at San Diego Comicon a few years ago - he's a hero based on the idea of going out with someone so your friend can go out with their friend, even though it's a bad idea. So his power is to just... jump on grenades.