Don't think so, so far Revs are the only mob I haven't been able to tame.
It's also starting to look like it's going to be one tamed animal per player for the time being.
If you are experiencing horrible LAG on test then blame the animal farmers near you, the more there are in a small area the worse it gets, a couple of pets aren't causing anything bad, but several dozen and the server and client have a hard time just drawing them let alone tracking them.