A Guthix wizard is a wizard encountered during elite treasure trails. He may appear if a player digs at a scan or compass location. He uses all three combat styles (melee/magic/ranged), and will almost always cause poison with melee. When encountered in the Wilderness, the wizard is level 126; elsewhere, he is usually level 133, although seldom he can be 126 as well outside of the Wilderness.
With the Magic attack, he uses Claws of Guthix to attack, which lowers Defence and can hit into the low to mid 700s. This attack is quite accurate and may hit hard, even with high levelled ranged armour.
With the Melee attack, the level 133 wizard uses a poisoned Dragon dagger to attack, much like the Saradomin wizard. The level 126 wizard encountered in the Wilderness instead uses a poisoned Mithril dagger. The melee attack is accurate and almost never misses. It will also cause poison nearly 100% of the time, whether it does damage or not (similar to Cave slimes), so some form of antipoison, an Anti-poison totem, or the Venomblood perk are recommended.
With the Ranged attack, he throws Rune knives. These knives do not cause poison.
The Guthix wizard adapts his attack style according to the stats of the player's armour and protection prayers, similar to Revenants. For example, if you wear melee armour, he will primarily attack with magic, and activating Protect from Magic will result in him using the next best style (melee). He is weak against arrows, so it is advised to bring ranged armour and the best bow the player can use to quickly dispatch the wizard. This will cause him to attempt to use melee most of the time to exploit your weakness to melee, which will likely result in you becoming poisoned (unless you have immunised yourself), so activate Protect from Melee, to make him use Ranged or Magic instead and prevent the risk of poison. He is not to be underestimated at any time, as he can hit hard from all three corners of the combat triangle, which can kill any under-prepared player in a matter of seconds.
Some players have reported experiencing glitches when encountering Guthix wizards while a combat familiar is following. The player may receive a chat message saying "It's not after you..." if the wizard targets the familiar; the player is then rendered unable to attack the wizard, and must dig again and fight a new wizard. It is advisable to not bring a familiar in case this occurs, or to use a passive familiar that does not attack (such as a bunyip or pack yak). Another option is to bypass the fight altogether by using Meerkats and Fetch casket scrolls.
The level 133 and 126 Guthix wizards are similar in appearance to their Saradomin wizard and Zamorak wizard counterparts, respectively. The only difference is that they wear a green cloak and robe, and the level 126 wizard wields a mithril dagger instead of a god staff.
Despite being level 126 in the Wilderness, it is also possible to encounter a level 126 Guthix wizard outside of the Wilderness. It is unknown if this is a mistake or oversight from Jagex, however the chances of a 126 wizard spawning instead of 133 are rare.
Unlike the other two god wizards, the Guthix wizards have sound effects when attacking (a 'stab' sound effect for the dagger and a 'throw' effect for their rune knives) and receiving damage (similar sound effects to forgotten mages). This is unusual, as the other wizards do not have any sort of sound when being inflicted with damage, and the Saradomin wizard does not have a sound effect when using melee.
According to the now-removed RuneScape Bestiary, their stats seem to be much stronger than most bosses although the health ratio is much different. Guthix wizards have 90/95 in their combat stats, while bosses like the Kalphite King have 240,000 life points but 85 in all combat stats.
There is an extremely rare glitch that enables the wizard to sometimes inflict poison when using Claws of Guthix, even if he does not use melee at all throughout the fight. This is actually caused by the routine that the wizard uses to poison the player. If the wizard is in melee range and the player is not using Protect from Melee or Deflect Melee, the wizard has about a 95% chance of causing poison for each game tick that passes. The first game tick could fail, for example, but the poison might be inflicted on the second or third tick. Activating Protect from Melee or Deflect Melee prevents this from happening by causing the wizard to instead use his non-poisonous ranged and/or magic attacks. The same glitch also affects Saradomin wizards.
When using his ranged attack, there is a graphical error that makes the wizard appear as if he is throwing dragon dagger/mithril daggers at the player. It does not poison the player and it has not been fixed.
There is currently a glitch with only the level 126 wizard where the sound effect for his successful magic attacks is that of Flames of Zamorak.