Rez was the supreme overlord of the Media Dimension. Once Gex's father, he fell into a scrap heap while trying to get free cable, and has rebuilt his body. Rez has been watching Gex for some time and plans to turn him into a bronzed network mascot and replace the NBC peacock. He yanked into the Media Dimension, and Gex has destroyed him the first time.
Rez, however, returned and regains control of the Media Dimension. A secret government agency was on his case and sent Gex to stop him again. After being defeated by his son, Rez tells Gex that he is his father, but Gex destroyed him by turning off the TV he's trapped in.
The following year, Rez seeks revenge on his son and kidnaps his partner and girlfriend [Agent Xtra]. He showed her his entire collection of Star Trek bloopers. And then he forced Xtra to marry him, when Gex aboards his Rez-Raker space station. Rez was destroyed once again.
It is not known whether Rez is truly dead or he's still out in the Media Dimension planning his next revenge on Gex, only prime-time will tell.
In the original story, Gex's father was working at NASA. He and ten other volunteers were chosen to see if they would eat tapioca pudding in zero-gravity. Their space shuttle exploded on the launch pad due to a band-aid floating in one of the fuel tanks.