OTHER NOTABLE APPEARANCES:
FANTASTIC FOUR #219 (note: this creature was smaller, and was theorized to be another member of the same race)
NAMOR THE SUB-MARINER #13 (in flashback only), #56
MARVEL UNIVERSE #7
Giganto was the basis for MOBY DICK, having fought with Ulysses Bloodstone, who took on the Ahab role.
Much later, Giganto was summoned by Namor to attack New York, but was driven back by the Fantastic Four.
A creature greatly resembling Giganto, but somewhat smaller was part of a group of monsters summoned by Captain Barracuda to attack New York. The creatures were defeated by the Fantastic Four and Namor.
Giganto was then brought forth by Llyra and Llyron in an attempt to attack the U.S. and blame Namor for it. Namor managed to make Giganto retreat by setting it on fire, and it then rushed back into the ocean.