they are the same appearence as the original adaptoid, but with green color.
The three where created by the Scientist Supreme.
They fight the Avengers each other the first one fights Iron Man, Captain America, the second one fights Black Widow, Hulk and Thor, the third one fights Hawkeye and Falcon.
During the fight all of them merged with the creator and formed the Supreme Adaptoid, the Avengers where no match for him until iron man found a weakness (which was to attack the adaptoid when they wheren't merged with the creator).
After they defeated the adaptoids a brocken Ultron emerged from the ground and absorbed the head of A.I.M.