The monsters are mad at Jimmy because he reminds them of their tormentor, an evil genius who’s been manipulating them for his own amusement. Insert Dan DiDio joke here, I suppose….
It’s from Jimmy Olsen Adventures By Jack Kirby Volume 2 — something to look forward to if you haven’t read it yet, Bahlactus!
[From “Genocide Spray!” in Superman’s Pal Jimmy Olsen #143, November 1971. Written and pencilled by the King, inked by Vince Colletta, “touch-ups” on Superman and Jimmy by (I think) Murphy Anderson, color reconstruction for the reprint by David Tanguay, lettered by John Costanza.]