The Slayer Tower shortbow was a very rare prize from Treasure Hunter. The bow provides the same bonuses as a regular shortbow, however does not work to light logs for barbarian firemaking. It was discontinued in March2015, with 1,500 being available in the rare token store.
It can also be obtained as a rare award from any shiny clover necklace variant.
It is a possible prize from opening antique chests during the Buried Treasure promotion and the Loot Duels promotion. However, it is not a guaranteed prize since the chest contains a variety of potential prizes.