noun, plural: nematocytes
Nematocytes are explosive cells commonly found in the animals of the Phylum Cnidaria (e.g. jellyfish, sea anemones, corals, hydrae, etc.). Each of these cells contains a nematocyst that shoots off a thread-like (often toxic) tubule that produces a paralyzing or stinging effect to the target animal.
Word origin: Greek nēmat- (thread) + -cyte (cell)