Any of numerous long-legged, slender-bodied flies of the family Tipulidae, having the general appearance of a large mosquito. Also called daddy longlegs. crane flies a flying insect with long legs = daddy longlegs. Harmless, slow-flying dipteran (family Tipulidae) usually found around water or abundant vegetation. It ranges in size from tiny to slightly over 1 in. (2.5 cm) long. Larvae of the range crane fly (Tipula simplex) are called leatherjackets because of their tough brown skin. In northern latitudes a wingless crane-fly species is found on snow. The crane fly is also called daddy longlegs in English-speaking countries other than the U.S. (in the U.S., daddy longlegs refers to an arachnid)