In Norse mythology, Utgardaloki was the ruler of the city Utgard in Jotunheim. He was one of the giants.

Utgard-Loki was one of the sharpest of the giants, a master of magic and illusion. He managed to trick mighty Thor, son of Odin, in taking part in a series of tests of his force. The tests were all rigged but Utgard-Loki's magic was so great that the god of thunder could not see that it was impossible for him to win.

Alternative: Utgart-Loki