The Bio Rifle is a weapon in Unreal, Unreal: Return to Na Pali, Unreal Tournament, Unreal Tournament 2003, Unreal Tournament 2004, Unreal Tournament 3, and Unreal Tournament 4. A testament to creative recycling, the Bio Rifle uses volatile green Tarydium waste for ammunition. The highly unstable nature of this sludge makes the Bio Rifle more powerful than its Tarydium shard-using cousin, the Stinger.