firecracker

Short definition from Wiktionary

Noun

1. 1
   A small explosive device, typically containing a small amount of gunpowder in a tightly-wound roll of paper, primarily designed to produce a large bang.
2. 2
   A peanut butter cracker baked with marijuana, similar in concept to an Alice B. Toklas brownie.
3. 3
   An individual who is quick-tempered, rambunctious, or unpredictable.