I don't know what Grodd's been smoking there in Gorilla City, but he certainly doesn't look like a mind-controlling, world-dominating super-intelligent ape to me in this picture:
But whatever it is, I bet he got it off of Angar the Screamer. That's the kind of crossover I think any self-respecting love child can endorse. Peace, happiness, and evil; the sixties live again, my friends!