One group of artifacts are the Arkentools which include the Arkenhammer, the Arkenpliers and the Arkendish. Parson's first Stupid Meal mentions there are four known Arkentools, but we don't know what the fourth one is.
Artifacts are magical items supposedly created by the Titans themselves and likely Pop into existence, unlike Magic Items which must be created by Casters. The Arkentools may actually not be Artifacts created by the Titans since they were supposedly used by the Titans to create Erfworld.
Prominent artifact-based factions include Charlescomm -- powered by the might of the Arkendish -- the regime of Stanley the Tool, who came to power through his possession of the Arkenhammer and regards it as a mark of his consecration by the Titans--and most recently Wanda with her acquisition of the Arkenpliers which she believes were destined for her by the power of Fate. While still claiming loyalty to Stanley the Tool, she does have her own units and symbol to form a side within a side.