What kind of caterpillar is black with a orange stripe down the back?

It's impossible to say for certain what kind of caterpillar you're describing without more information! There are many caterpillar species that share this general color pattern.

To help me narrow it down, could you tell me:

* Where did you see the caterpillar? (Location, specific plant, etc.)

* What size was it? (Tiny, medium, large)

* Did it have any other markings? (Spots, hairs, spines, etc.)

* What was it eating? (Specific plant, if known)

Once I have more information, I can help you identify the caterpillar!