That pesky Red Kryptonite changes Superboy into a monkey, who immediately gets a gig as a organ grinder's monkey. After causing general monkey-mayhem, the Red Kryptonite's "secondary, delayed effect" causes Superboy change into a giant ape!Pretty soon, Beppo, the Super-Monkey shows up, and the Red Kryptonite changes him into Superboy. Eventually, the Red Kryptonite's wacky effects wear off, and the two revert back to normal.
Suddenly, on the last page, Beppo has a Red K-relapse, and turns into a giant Superboy -- but this gives the two an oppertunity to convince Lana Lang that Clark Kent isn't really Superboy ("Good Grief! The ape was really Superboy, all right! So Superboy can't be Clark!"). Whew, that was close.