The Eurasian hobby (Falco subbuteo) or just hobby, is a small, slim falcon. It belongs to a rather close-knit group of similar falcons often considered a subgenus Hypotriorchis.
Adults are slate-grey above with a dark crown and two short black moustachial stripes. The throat is unstreaked white, thighs and undertail coverts are unstreaked rufous and rest of the underparts are whitish with black streaks. Close views enable the red "trousers" and vent to be seen. Sexes are similar. Juveniles are generally much browner, with scaled upper parts and streaked buffy thighs and undertail coverts