Namor

Namor the Sub-Mariner once attended Bonjaxx's birthday party at Maruthea. (COMIC: The Incomplete Death's Head)

Behind the scenes
Namor the Sub-Mariner was not named in COMIC: The Incomplete Death's Head but is distinguished by his pointed ears, short black hair, widow's peak, and arched eyebrows. Furthermore, the aquatic aspect of his person is represented by his "save the whale" badge and skeptical look at the fish in his drink.

First published in 1939, he is the first superhero created by Marvel comics (then known as Timely Comics), and if fittingly has the most prominent cameo in The Incomplete Death's Head.