The cookiecutter shark (Isistius brasiliensis), also called the cigar shark, is a species of small dogfish shark in the family Dalatiidae. This shark occurs in warm, oceanic waters worldwide, particularly near islands, and has been recorded from as deep as 3.7 km (2.3 mi).
The Smalltooth Cookiecutter Shark gets its name from the unusual way it feeds. Its impressive teeth are used to carve out a cookie of muscle from its prey, which includes larger fishes and mammals (including humans). Despite its taste for large prey, the species only grows to about 50 cm in length.