He's not listed, but he is a summon. You probably think I just got the name from Advent Children, and yes he is from that; but he's also a summon in VI, IX, and XI. I've only played VI, but I really like him. Mostly because he's a wolf. Hehe.
But I also like the mythology behind his name. Norse mythology is one of my favorites. Fenrir is the beginning of Ragnarok. Much fun. XD
I also wanted something different. Something not normally thought of. He seemed the best bet. And lo and behold, he's not on the list. ^_^
Anyway, can I have him? Oh, and Atomos could be added to the list too ya know. He's a summon also.