The poplar grey (Acronicta megacephala) is a moth of the family Noctuidae. It is found throughout Europe. This species has dark grey forewings mottled with black and marked with pale stigmata, and white hindwings. Melanic forms sometimes occur. The wingspan is 40–45 mm. This moth flies at night from May to August and is attracted to light and sugar. The hairy larva is grey with black and red markings and a white patch towards the rear. It feeds on poplars and willows and sometimes on grey alder. The species overwinters as a pupa.