The ham robe is a skirt worn by H.A.M members, and is the bottom (leg-wear) part of the H.A.M. robes set. When worn, players are slightly less likely to be kicked out of the H.A.M. Hideout when pickpocketing male and female H.A.M. members after three failed attempts. Wearing this will not increase player's chances of success pickpocketing, however.
It can be acquired either by pickpocketing H.A.M. members or by killing H.A.M. guards, or by trading with other players. It is not sold in any store.