Not sure if you still need the clarification but basically here is the cliff notes (Spoilers for volume 1)
His official name is Antonio or "Tony." but after he found out about Jack's blog and reminded Jack that using his real name would be a big privacy violation (And potential evidence for the several Kifer murders) Jack changed the name to Carlos on the blog. If you want to know more buy the books.
Not sure if you still need the clarification but basically here is the cliff notes (Spoilers for volume 1) His official name is Antonio or "Tony." but after he found out about Jack's blog and reminded Jack that using his real name would be a big privacy violation (And potential evidence for the several Kifer murders) Jack changed the name to Carlos on the blog. If you want to know more buy the books.
Basically.... Cony.
In volume one it's revealed that his name is actually Anthony(Tony).
A fan sent in a letter asking for a character to be named after a friend who's name is Carlos.
At one point when Tony learns that Jack has a blog about his work life, Tony asks Jack to not use his real name for legal reasons.
Hence on the blog he's Carlos and in the book he's Tony.
Casper?
Yes.
I thought his name was Stabbins... I may be wrong though.