Sir Arthur is a colossal mechanical knight from the series Knights of Guinevere. He has a grinning golden mask-like face resembling a human's in the center of his chest, with a sun-like corona surrounding it. There is a crack down its left side, passing over Sir Arthur's left eye. Upon activation, this face lights up bright yellow.

Much of his body is covered in plate armor, with some exposed joints and wiring (especially at his waist). Pipe-like spikes extend from his pauldrons. He also wears a long, flowing cape.

He carries an oversized sword with star-like patterns in his left hand, while his right arm is larger, clawed, and seemingly entirely made up of long, thick thorned vines that descend to the ground.

It is also presumed that he contains organic parts or some sort of internal liquid similar to blood, since he bleeds when attacked.

Sir Arthur is a loyal soldier of Park Planet and Olivia. True to his knight-like appearance, he speaks in a old Shakespearean dialect and has a twisted form of their mannerisms, though still has a single-minded focus to complete his mission as would a machine. Although Sir Arthur is an obedient machine, it appears that he is capable of feeling emotions.

Sir Arthur was one of two titanic sized machines created by Olivia Park in her old age.

Light Projection: Sir Arthur's sun-themed face is capable of casting a blindingly bright beam of light in a focused area, similar to a searchlight.

High Strength: Sir Arthur is shown to be incredibly physically strong, able to lift an entire building in the lower labs and throw it with relative ease.

Limb Extension: Sir Arthur's tentacle-like arm can extend to several times its typical length.

Large Size: Sir Arthur stands at a intimidating size, towering above average humans.