The Guardian of Desire who makes several appearances in the Wild Arms franchise. Luceid's gender is not very specific at times - in the first game, Luceid is female, while in the second, Luceid is stated as male. His/her role also changes with each title, either being important to the story or just being a regular summon.
Of the Guardians, Luceid is the only one who can maintain physical form on Filgaia, often as a purple-furred wolf. Luceid is known to partner with people who have strong desires, such as Boomerang Flash and Anastasia Valeria. There is speculation that the white dog Tony in Wild Arms XF is Luceid, but there is no definite proof.