Craig’s past, but not his future.
 
I’ve been sitting on this for a while, but here it is; Craig is trans male. Born as a filly named Caballine, Craig transitioned in his forties (ie: young adult) shortly after realising his domain (Knowledge), putting in countless hours of research to find a solution. All in all, Craig wasn’t that much different in his youth than he is in the present day, aside from a lack of confidence and an unhappy air that Caroline had always found perplexing.
 
Rick, always one to know when something’s bothering his twin, was completely supportive upon finding out - sister, brother, whatever, Craig was his twin, his first and closest friend in life, and nothing would ever come between that. There were always fears that the rest of the family wouldn’t be so understanding - ultimately, he had nothing to worry about.
 
Barely anyone else really knows about Craig’s origins in the present day, almost two and a half millennia later - anyone who’d attribute his profession or general affinity for pink as a testament to ‘being a mare’ would probably get punched in the mouth, the idiots.