The Earth-Shaker first appeared in Nova #5 (January, 1977) and immediately brings to mind the old Nazi Sleeper robot from the Cap stories in Tales of Suspense. For some reason, Tyrannus (why does he repeatedly come back for more punishment?) has taken control of the Mole Man's mole people. Using slave labor and parts acquired through unexplained means, he has built this massive robot designed to destroy the surface world by burying it under rubble, leaving Tyrannus in charge of a fully subterranean world (or at least, I think that was the plan). While there is a bit of a battle, it really doesn't take Nova very long to put the Earth-Shaker out of its misery. He has a much tougher time with the Marvel Comics bullpen, as Marv Wolfman and Sal Buscema meet with Nova in an effort to pitch a new series to Stan Lee. Ultimately, Stan shoots down the idea with some cornball jokes that were stale in the 50s. The Earth-Shaker was a pretty lame robot, but at least he got Jack Kirby to draw him on the cover. I believe this image was even used for a Slurpee cup.