Bear in mind that there are
Naming Rules & Regulations and such rules are especially enforced on strict serves such as RP realms, mostly it's about players on the server reporting and then blizzard acting on it.
That being said, I've seen all manner of names and have a few myself that violate the rules so don't take it as me telling you not to have some fun, as long as it's good clean fun.
Here are a few Tauren names I've used and seen, note they all fall under the humor category:
Tipthis
Chuck
SirLoins
Moostaffa
(Great for a caster Tauren, as you generally use staves/staffs, whatever, but some people CAN (and have) construed it as an NEGATIVE racial joke)
IGiveYouWings
(If it's a Reddish/Brown colored Tauren, Red Bull, get it? :P)
and my personal favorite BullCosby
Happy naming.