Calling it Anubis would be baddd. ;/
And any not easily recognizable name is bad too, IMO. :/
"Sounds good" and "pronouncible" aren't enough qualifications on their own IMO..
They need to be cool like "The Rook". =]
A name like "Dr. Acula" is much easier to remember, and is a cool play on words. So is the "The Rook", it's a 'cute' reference to the piece in chess! Fits perfectly!
Unclean Beast makes perfect sense for the unit, intuitive and easy to remember. If it was named "Shinigami" instead, how would you connect that in your mind to remember the beastly disease dirty dude is supposed to be named that? After a while of playing you'd remember, but it doesn't pop right in your head right away like Unclean Beast does.
I still like Betelgeuse though.

It's also intuitive.