This monster's missing eye appears in the artwork of "Runick Fountain".
This is a reference to how Odin sacrificed one of his eyes to Mímisbrunnr ("well of Mímir"), which "Runick Fountain" is based on, in exchange for a drink in the well. Mímisbrunnr is one of the three wells located beneath the roots of the world-tree Yggdrasil in Norse mythology. It is said that the water of the well contains vast wisdom.
The symbol from the artwork of "Generaider Boss Stage" appears in this card's artwork (although the top circle is highlighted dark blue.
This monster is based on Odin, one of the central gods in Norse mythology.
This card's name, "Harr", is a reference to one of the numerous names of Odin: "Har" ("high").
The symbol from the artwork of "Generaider Boss Stage" that appears in this card's artwork is based on Asgard, the home of the Æsir gods.