Oven Knight

Guardians are an enemy added in v1.8, the Bestiary Update. They appear to be mechanical in nature, being powered by a furnace in their chest. They will only begin to appear in biomes on 2 BSC and above. They can appear in a handful of areas, and can pose a significant threat to inexperienced players.

Behavior
The Guardian wields a breakable wooden shield that absorbs attacks from the front. It will bump the player when hit with a melee attack, but not as much as the Shieldbearer's shield. Whips and parries will not deal damage to the shield. After the shield absorbs enough damage, it will break and the Guardian will change behavior.

Guardians patrol the area slowly while they have their shield up, and even when they detect the player, they will continue to walk at a slow pace. When their shield is broken, they will become more aggressive and move much faster.

Strategy
Guardians have two different movesets based on whether they have their shields or not. While they have their shields up, they are vulnerable from behind. Their shield bash attack comes out pretty fast however, so be prepared to roll away from it as soon as they turn around. If you do get by the shield bash, mash roll and hope you roll out of its follow up attack.

Without their shield, their attacks are more aggressive. If you try to roll behind them right when they start to attack, there is a very high chance the second swing will hit you. If you see a Guardian running at you, roll away to dodge the first hit, then approach it after the second hit to hit it at melee range. If you need to roll behind it, do it at the last second and jump away to minimize the chance of getting hit.

If a Guardian is far away enough from you, deal with the other faster enemies first. At 4+ BSC, run away to a longer platform if you need to.

Whips (Valmont's Whip, Wrenching Whip, Electric Whip) can easily kill Guardians, letting you hit them past their shields at a distance far from where they can reach you.