The H.a.m. cloak is a cloak or cape worn by H.A.M. (Humans Against Monsters) members. Wearing it increases the chance of successfully pickpocketing a H.A.M. member. It can be obtained by thieving H.A.M. members or by killing H.A.M. Guards. H.A.M. clothing is usually worn for show, although it is a requirement for the Death to the Dorgeshuun quest.
During the Triumvirate, players who decided to join the Reavers wore the H.A.M. Robes to blend in, and then attack their enemies with a poisonous weapon. However, they often got recognised on the minimap.
A regular H.A.M Member appears to be wearing a plain pink cloak with no symbols on it. The player-worn one however, appears to have the H.A.M. logo on the back of it.