From an observation of the original art, Nick Caputo explains: "The cover was originally completely drawn by Marie Severin and inked by Frank Giacoia, but Stan apparently did not like how the Asgardian figures looked and asked Jack Kirby to re-draw them, with Syd Shores inking, thus the mixed cover elements." Information provided Jan, 2012.
Continued in The Incredible Hulk (Marvel, 1968 series) #102.
NOTE 1: Sub-Mariner is continued in Iron Man and Sub-Mariner #1, and then in Sub-Mariner #1. NOTE 2: First hint of Destiny, soon to be a major foe. NOTE 3: Letterer changed from Gaspar Saladino (as LP Gregory) to Artie Simek as per printed credit.