I've always been a fan of Hank Pym, scientist first and superhero second (sounds like Reed Richards too, huh?). Over the years, he changed his costume and even his Superhero name multiple times (when in complimentary super-size mode, he was also Giant Man, and later Goliath, not to mention the time when he switched his normal red togs for yellow and black ones and started calling himself Yellowjacket, with no memory of his other identity).
Regardless, his contributions to the Avengers (along with his wife, Jan, otherwise known as the Wasp) have been significant, even if there WAS that little slip up of creating one of the most powerful super villains in existence, Ultron (hey, everybody is entitled to one mistake, right?)
Here's some reference shots of Dr. Pym aka Ant-Man (before he added the Cybernetic helmet). This was my favorite "look" for him, and how he appeared back when he helped "discover" Captain America frozen in that block of ice ....
- The head and body were from a Buzz Lightyear POP, repainted.
- The obligatory antennae were added.