The external morphology of last instar larvae of Phauda mimica Strand, 1915, from Taiwan is described. The slug-like larvae are glossy brownish white in coloration. Dorsally they are covered by a tergal cap consisting of a dense mesh of irregularly interwoven silk fibres with additional cellular elements and hardened incrustations. This peculiar structure is not known from other Lepidoptera. According to the present morphological findings, the genus (along with allied genera) does probably not belong to the Zygaenidae, as hitherto suggested, but rather represents the sister group of the limacodid-group families currently comprising the (Megalopygidae/Somabrachyidae + (Aididae + (Dalceridae + Limacodidae))).