Spoiler: One of Caro's concept-design sketches and a little insight of his character background.
(There's another one but like every good sadist artists, I'm only giving one piece at a time uwu)
Caro is the outcome of "What if not the Ringmaster, but the Ringmaster's brother caught the twins?" (It's no secret: The "Ringmaster" is the main villain in Twin's past) That brother does have a rough design but no name currently. He's not important for Pit's past but he's the main antagonist in Goreas' and Gaster's backstory.
My first approach for Caro was the Underfell feeling, mixed with the casino-theme but that does not really fit. Caro's "master" is rich and the owner of a wealthy casino. Making Caro look like a smoking streetfighter is not really fitting, considering who his "master" is.
(This AU has slavery btw. At some point I was thinking of removing it to make it more kids-friendly, but I'll keep it in. Otherwise TTale's backstory wouldn't make sense)
Since I started working on the upcoming manga (and parallel working on Goreas & Gaster's backstory because their past and the Twin's past are playing parallel to each other) a new design for Caro came to my mind. His "master" is supposed to be themed around a silver fox (he's still a human), so giving Caro also a fox-theme fits very much. But Caro is mostly active in the dark and in shady areas, so giving him a dark-design is still important.
The reason why Caro is called Caro, like that one card-symbol, is because close "workers" of Caro's master have a card-theme. As you might guess, there are 3 others. Though, their designs are still a WIP since they're not important for the current comic-story.
Caro still drinks whisky and smokes... just not around Frisk because that kid would 100% take it and try it. When his design is done, I NEED to show how cute those two are! Caro is like a grumpy uncle while Frisk is a happy kid with no survival instincts! >w<//
