The Brain and Ultra-Humanite took over control of Solovar's group, and enslaved all its gorillas with inhibitor collars. Like the other adults, Grodd was experimented upon with Kobra-Venom, which greatly improved his strength. He was also given brain enhancements that increased his intelligence. It also gave him telepathic abilities, a side effect unforseen by their tormentors. Solovar and Grodd became peons of Brain and Ultra-Humanite, who made sure they did not rebel by capturing their children.