I'm thinking it's worth adding a category for Images of BabyGriz... her costume is so different to Grizabella's, and it's interesting how she's changed from one production to another. We know her name is used backstage as Babygriz. She's clear cut.
Similarly, thanks to the video we have a clear separation of "Gus the Theatre Cat" and "Asparagus" his ensemble identity, despite the overlap towards the end of the show.
But what do we call the other two ensemble Cats we see in the opening? Tugger and Deut both have notably different looks - and Tugger's ensemble look hasn't changed from Rockstar to Street Cat. I've vaguely seen "Baby Tugger" around, but he's not baby in the way Griz is a vastly younger version of the same character. "Young Deut" seems appropriate... but do we know what those costumes are called backstage?