Illococoo

Sylphid (シルフィード Shirufīdo) / Illococoo (イルククゥ Irukukũ) is a female rhyme dragon and Tabitha's familiar. She looks like a mother or an older sister of Tabitha when she is in human form, but she refers to Tabitha as "Oneesama" which means "older sister." Though she is sensible, she is sometimes childish. Sylphid doesn't live in the Academy like other familiars because she's too big (as a dragon), so she stays in a neighboring forest. She promised to her "older sister" that she would not tell anybody about her ability to use nature magic (which allows her to shift between forms), but Derflinger eventually found out about her secret.