A mounted cockatrice head can be built in the head trophy hotspot of the Skill Hall in a player-owned house. Upon building it, players will receive 224 Construction xp and 294 Slayer xp.
Players can only get a stuffed cockatrice head by killing Cockatrices, requiring 25 Slayer, until they drop a cockatrice head. Players must then take the head to the Taxidermist in Canifis, who will stuff it for 2,000 coins. Once mounted however, the head cannot be reclaimed. If players remove the mounted head, they will receive nothing back. Jagex has stated that this is because mounting the head rewards Slayer xp, and they did not want players to be able to train Slayer by removing and remounting the cockatrice head.