Red Ghost of the Sea

Defenders #7-8 creatively repurposed an establish character. Red Ghost, who had demonstrated the ability to mentally command apes after bombarding them with cosmic rays, found them increasingly difficult to control. As a result, the villain decided to try out his power on porpoises—also highly intelligent mammals and perhaps more responsive to his commands. Red Ghost's new modus operandi found him an ally in the Atlantean conquerer Attuma.

Red Ghost tried to expand his powers even more, using advanced technology to mentally command Sub-Mariner, and then Valkyrie and Hawkeye (during his short time with the Defenders). The mental tampering had a side effect for Valkyrie, who as already internally conflicted with the mind of of Barbara Norriss, causing her to hallucinate monstrous images (foreshadowing events in Defenders #64).

Dr. Strange ultimately freed the others from the influence of Red Ghost by creating a mystic shield to prevent cosmic rays from reaching Earth.

This panel of Red Ghost comes from Defenders #7 (Aug. 1973).