Agent AA is Jay's partner in the alternate 2012 in Men in Black 3. He seems to annoy Jay with his constant fast talk. Jay doesn't know who he is and doesn't understand that the timeline has been changed resulting in an alternate reality where Kay had been dead for 40 years.
AA is portrayed by Will Arnett.
When Jay arrives at MiB Headquarters to look for Kay. AA appears to stand next to him as he enters the elevator. He begins to talk to Jay about everything that he said to him yesterday but Jay doesn't know who he is and doesn't realize that the timeline has been changed resulting in an alternate reality where Kay had been erased from existence after his past self was killed by Boris the Animal who had gone back in time to kill Kay's younger self. AA keeps on talking to Jay as if they are partners and Jay tells him to keep his distance away from him.
AA after getting off the elevator tells Jay that he's going to bathroom then they'll set out to find the aliens and says "Lunch is on me" before slapping Jay on his rear end. As he left Jay asked another Agent who that guy was and was told that he is AA and is Jay's partner. Jay later realizes that the timeline has been changed when he learns that Kay had been dead for over 40 years.
After Jay with help from Kay's past self restores the timeline, he returns to the restored 2012 where he finds Kay in a diner. Due to this it can be assumed that AA didn't exist in this timeline and Jay and Kay were still partners.
- Will Arnett sign on to make a cameo appearance as Agent AA in Men in Black 3.