bombardier beetle

Short definition from Wiktionary

Noun

1. 1
   A beetle whose defence mechanism enables it to eject a hot aqueous mixture of chemicals at predators. They come from a number of subfamilies: Carabinae (e.g., Brachinus crepitans), Metriinae (e.g., Stenaptinus insignis) and Paussinae (e.g., Goniotropis nicaraguensis).