Guthan the Infested is the third oldest of the six Barrows brothers. Guthan's crypt is located at the south-east of the Barrows area. He uses melee equipment, which make him vulnerable to Magic attacks. Guthan's set effect is Infestation, which gives him a 25% chance per successful hit to heal him for whatever damage is dealt for that hit.
Guthan is often regarded as one of the easier brothers since he is inaccurate compared to most of the other brothers. He attacks using a warspear, so armour defensive against stab is advised. Despite his inaccuracy, he can still hit up to 24 so the use of Protect from Melee is advised for players with low Defence. Players who get hit often may also cause his set effect to activate more and thus he will heal more, making the fight longer. Using Protect from Melee also prevents his set effect from activating.
Guthan is commonly defeated with the use of a trident of the swamp/seas, Iban Blast or Magic Dart. Players can also use Entangle or Ice spells on Guthan to attack him from a distance.