The English name of this monster means "Sea Dragon God", and is a literal transliteration of the kanji in the Japanese name of this card. However, the ruby text above these kanji indicates that the Japanese name should be read as Leviathan, not Kairyūshin.
Leviathan (Hebrew: לִוְיָתָן, Standard Liwyatan Tiberian Liwyāṯān ; "Twisted; coiled") is a Biblical sea monster referred to in the Old Testament (Psalm 74:13-14; Job 41; Isaiah 27:1). The word leviathan has become synonymous with any large sea monster or creature. In the novel Moby-Dick it refers to great whales, and in Modern Hebrew, it means simply "whale".
The Bandai version of this card is Level 6 and has 2200 ATK & 2000 DEF, whereas the Konami card is Level 5 and has 1800 ATK & 1500 DEF. Moreover the Bandai version is violet and the Konami version is blue.
Artwork-wise, "Yormungarde" is a counterpart of this card.