Avengers #100 (Marvel, 1972)

Avengers Assembled! A truly momentous occasion, as this page from the 100th issue of the title features nearly everyone who had ever been an Avenger up to that point! Barry Windsor-Smith turned in a fittingly momentous image for this spread.
The Avengers Roll-Call for this piece includes: Iron Man, Thor, Ant-Man and the Wasp, the Hulk, Captain America, Hawkeye (in his 'hippie' costume), Quicksilver and the Scarlet Witch, Hercules, Black Panther, and the Vision! (And even a future Avenger with Black Knight.) Can you guess who the missing member was?