User blog comment:Kogath/Monster Hunter 4 Ultimate for the Nintendo 3DS/@comment-1758220-20140128014305/@comment-1758220-20140129204201

Anything like Black Tigrex, Jet Tigrex, Ebony Tigrex, Obsidian Tigrex, etc. I think are all poor bets. If you look at him, the Tigrex Sub pretty much isn't even black.

http://static3.wikia.nocookie.net/__cb20140106104840/monsterhunter/images/e/e3/MHP3-Tigrex_Subspecies_Render_001.png

At his darkest he's a deep dark brown. In other places he's beige and even olive green. I actually don't think there's a lick of genuine black on his entire body except maybe the end of the tail. Therefore, any name that implies a pitch black or even mostly black colouration is extremely off the mark it seems.