I think this may have been one of the rarest spawn events in SOTA: I was in the Breach, when a Purple Llama and a golden clockwork dragon spawned together! (for more info on the purple llama, see this post in the easter egg thread)
Sadly, I am reasonably sure that the purple llama (in-game, it is actually called "An Energy Vortex") is not tamable. Also, it does not drop loot. See the link in my first post for all the details (and pics) of the purple llama.
I saw it too a few weeks ago, I started to kill it but it was so pink and so cute that I felt sorry for it. Also, I would be unable to kill a UO memory