Wilson seems calm and relatively friendly. He's enthusiastic about getting a hamburger after having spent a long mission in space, stating that they don't have hamburgers in space. It is revealed that Wilson has a deeply traumatic memory of being trapped outside of his spaceship in a spacesuit that was quickly running out of air after lending a fellow astronaut his headphones. He begins to freak out but soon calms down after being assured that he would get his hamburger.
Wilson is a relatively average looking man with pale skin, dark eyes, a pointed nose, and a strong, square jaw. He has very short black hair and heavy lines under his eyes. Wilson is seen in his space suit, carrying the helmet in one arm.
“The parade must be for that astronaut!” “Oh, it's not for that astronaut. This parade is celebrating the one hundred and fiftieth anniversary of ticker-tape parades.” “Then what's the astronaut for?” “They're just giving him a ride somewhere. Very slowly because he likes to sit up there.” —Milo, Melissa and a janitor[source]
“I... never... should have given him those headphones!” —Wilson about Larry[src]
Wilson is likely a reference to the film Apollo 13, as he is voiced by Jim Hanks, who is the brother of Tom Hanks (who starred in the film).
Wilson is also the name of the volleyball in a different Tom Hanks film, Cast Away.