Botulinum toxin
Botulinum toxin, botulinum neurotoxin, or botox is a neurotoxic protein produced by the bacterium Clostridium botulinum and related species, and it is considered the deadliest known natural substance ever recorded in chemical literature. It prevents the release of the neurotransmitter acetylcholine from axon endings at the neuromuscular junction, thus causing flaccid paralysis.