Reprints X-Men (1963) #41 and a 5-page story from Amazing Adult Fantasy #11
"Now Strikes... The Sub-Human!"
A sub-human creature roams the subways, lost and confused until he remembers he was a prince of a great underworld empire that was wiped out by a volcano. Swearing revenge on the surface dwellers, the sub-human plots to destroy humanity. Meanwhile, Dr. Hunt unveils his earth tremor machine to the Board of Trustees for the college, as he gives them a sample of what it can do, it shakes the Sub-Human who climbs back to the surface to find the machine and use it against humanity.
"For the Rest of Your Life!"