Thysania agrippina is a species of moth in the Erebidae family. The species has numerous common names, including white witch, birdwing moth, ghost moth, great grey witch, and great owlet moth. It is the lepidopteran with the biggest wingspan, which typically is reported as being up to 27–29 cm (11–11 in) and one Brazilian specimen had a wingspan of almost 30 cm (12 in). The Atlas moth and Hercules moth, however, have greater wing areas. The species occurs in Mexico, Central and South America, and appears as a stray as far north as Texas, USA.
The species is generally widespread, but is considered endangered in the state of Rio Grande do Sul, Brazil, where it reaches the southern limit of its distribution.
No confirmed rearing records are available for this species. Based on reports for sister species Thysania zenobia that feeds on Senna and Cassia, the larval host plants for the White Witch are probably also woody members of Fabaceae (subfamily Caesalpinioideae).