Known artifacts are the Arkenhammer, the Arkenpliers, and the Arkendish collectively referred to as the Arkentools. One of Parson's Stupid Meals mentions there are FOUR known Arkentools, but we don't know what the fourth one is.
Artifacts are powerful magical items supposedly created by the Titans themselves. Each is unique, priceless and possessed of vast powers that can be used by anyone fortunate enough to both acquire one and become attuned to it. Wars have been fought over less - and the power of artifacts can raise and lower rulers and kingdoms.
Prominent artifact-based factions include Charlescomm - powered by the might of the Arkendish -- and 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.