DoR Frog with moustache and gun
Like many other characters, Frog have a dimensional counterpart in the dimension of Rain. The destiny of that dimensions Frog is revealed in the very end. Therefore, all things regarding DoR Frog is a major spoiler for the 4U City story arc.
SPOILER WARNING
This section blatantly gives away the mysteries and/or endings of the storylines 4U City.
If you haven't read some of those stories, then dude, before you go any further, go read them![1] This stuff will still be here when you're done.
You have been warned...
Frog is discovered to have been in hiding with DoR Dr. Schlock all along, possibly assisting him in being His Masterness. When DoR Riff finds them, Frog already have a mustache and a pistol, and might already be insane. After Schlock dies and leaves a post-mortem message telling Frog the truth about Corsica, Frog displays erratic behavior and DoR Riff later referes to him as "an insane frog".