After he gained his special abilities and a face that looked like an avocado had sex with an older, more disgusting avocado, Wade visited Weasel to tell him he was still alive.
Within the X-Men film universe, T.J. Miller’s Weasel runs a bar that is frequented primarily by mercenaries, including Wade Wilson pre-body scarring.
Within the Deadpool mythology, Weasel (real name Jack Hammer) is one of the more important characters, typically serving as Deadpool’s best friend, although their dynamic is such as that Deadpool frequently mistreats Weasel and Weasel is so self-interested that his schemes often screw Deadpool over.
While their friendship is more healthy than it is in the comics, when it came time for Wade to rescue Vanessa from Ajax and Angel Dust’s clutches, Weasel didn’t tag along simply because he didn’t want to.