Crocos have a boss monster card

Check him out ingame. More precisely, the Showa set. To complete that set, you need to kill both the one on the streets and the hideout one. Both with a white outline though.

Yes that was exactlly what i wrote. Takebacker refered to that enemy as The Boss, which is wrong since The Boss is the one the old gigantic headed end boss in the hideout. There are two Male Boss monsters, and they look the same, however as you say, they have separate entries in the book.

He has two forms but he's essentially the same thing thus he has 2 cards. It's like if tonosama had two separate cards one for the human and one for the toad. There would be two cards but the monster is basically the same.

My point was it is not The Boss but Male Boss. And no, Male Boss does not have two forms like Castellan. There are just 2 separate monsters with identical looks.