Grodd received his powers from exposure to a meteorite. This meteorite also affected King Solovar and the residents of Gorilla City, creating a hidden tribe of hyper-intelligent apes. Gorilla ...

In the source material, Solovar was brought from Gorilla City into the Monitor's alliance. He helped Kamandi defend a tower from the Anti-Monitor's shadow demons. They got aid from other heroes ...

There, Grodd is often seen squaring off with Solovar, another super-intelligent gorilla, for control. Unless Grodd somehow finds his way back to Earth-1 and finds its version of Gorilla City ...

13. Grodd Friended Me - Barry conducts an experiment that goes awry and puts him directly in Gorilla Grodd's path, but is surprised when Grodd asks for his help against another villain - Solovar ...

13. Attack on Gorilla City - Barry and the team travel to Earth-2 to rescue Harry from Gorilla City, where they're captured and brought to Grodd, who claims he needs their help to stop Solovar ...