Jellicle Cats

Jellicle Cats, along with Traditionalist Cats, are the two original groups of Cats created by The Architects.
Jellicle cats embody the chaos, creativity, and freedom of the Cat Heavens, and manifest in death as the Heavenside: a part of the Cat Heavens devoted to whimsy, imagination, and possibility. The Heavenside serves as the judge of all Jellicle creations and ironically keeps such a stranglehold over Jellicle culture that the group is unusually homogenous in their naming and expression. What began as total freedom has become a traditional dogma of re-enacted whimsy catering to an audience of dead Jellicle spirits that only want more of what they consider familiar. 
Jellicles must organize themselves into 'Courts' and assume set roles within those courts to commune with the Heavens. Through their embodiment of their chosen role, Jellicles create art pieces and musical numbers about them and their daily lives. Each year, the Jellicles host a festival, ball, holiday, feast, or other night of communion where they perform their pieces and announce their role to the Heavens. During this night, the Heavens will physically ascend one of their number to Heaven to watch over the court. Bodily ascended Jellicles then serve as a spiritual chain through which other members of the court are taken to Heaven after death. When all who know them have died and they cannot lift any others to heaven, an ascended Jellicle may either retire to heaven or reincarnate. 
Jellicles are often urban cats, while Traditionalist Cats are usually rural. Jellicles need props and opportunities for more varied social roles to thrive: having everyone be a Hunter makes for an unappealing Ball. Jellicles, like Traditionalists, are proselytizing and often seek out new converts among the pets and strays of cities. 
Jellicles were created by The Masked One. Their system of divine communion is directly taken from Cats the musical, but is not limited to the musical's lore or specifics - that was just the framework chosen by that Architect.