Cave just walked right into Zecora hut and began to look around. He also began to mess around with some spells and potions. And as a result turned himself into a centaur alicorn is it an alicorn centaur either way. Now he has a total of six limbs. Lesson here is never mess with stuff that isn't yours or experiment unknown substances.

*walks into her hut*
clop clop clop
Hmmmm nice place for a Zebra. Lets see what does she have in these bottles and spell books. Only one way to find out.
*starts chanting the spells and mixing the spells*
Whoa! what's happening to me? I'm starting to grow a third set of limbs.
Just imagine Zecora's expression when she spots him in her hut. "Huh? Who are you? No, what have you done." Not sure if you can go back to your regular self. I'm afraid you are stuck like this forever.
*Cave gasps with fear*
Noooooo!! :-O Hmmm I guess I could get used to this for a while.
*Lord Tirek (centaur spirit) sniffs the air*
Sniff sniff sniff
I smell a centaur alicorn mare and its somewhere in the evergreen forest.

Uh oh! Cave better watch out. Lord Tirek could be coming for him and suck out his alicorn powers....or worse. Looks like he's gonna need all the help he needs from the Mane Six and other fellow ponies to help defeat Lord Tirek.

MLP TF by