some sort of caterpillar?

Found out it is a Gulf Fritillary Caterpillar.

http://www.butterflyfunfacts.com/unusualgulflarvae.php

Is it a good or bad bug...wasn't sure if I should kill it or not.

What hoosierbanana said.  I would say in your case a good bug because they primarily eat passion flower.  If your a passion flower vine different story :)

well....I do have passion fruit vines....don't see many holes on the leaves.....hmmm maybe I should kill it  

A good-sized, healthy vine can probably handle a few caterpillars. If you like having the butterflies around, sacrificing some leaves might be a good trade-off.
 

I don't kill them or orange dogs. Mocking birdsuuuuuuuuuuu

it's funny, all these time I thought we were hosting Cardinals... I guess they are not...

         

Now, when you see a white battery with a single black dot on it's lower outer wing, KILL IT! that's what will eat all your Kale, Chard, Cabbage, Mint, Basil and lot more stuff you would want to grow and eat yourself.
This is what they will look like when you catch them, on the act, under leaves (never on front of the leaf).
it's true what they say about, You Are What You Eat.