Aquaman #34

Aquaman #34 (On Sale: May 2, 1967) has a nice cover by Nick Cardy.

Inside we have "Aquabeast the Abominable" by Bob Haney and Nick Cardy. While diving near his yacht millionaire Peter Dudley accidentally snares Mera in a net. Dudley falls in love with Mera, but realizes that Aquaman stands in his way. He pays Dr. Hans Ludorf to alter his appearance to match that of the Sea King. Unfortunately, the procedure goes awry transforming Dudley into a mutant Aquabeast.

Aquabeast soon invades Atlantis and kidnaps Mera. With superior strength granted him as a result of the transformation, Aquabeast also defeats Aquaman. As he flees the city with Mera in tow, Aquabeast runs into a race of demonoids which attack him.

Edited by George Kashdan.