Luna Varga is a oVA anime that premiered in spring 1991, produced by AIC.

About the production: the story comes from a light novel, there are 4 episodes of about 30 minutes and its current status is "finished".

Its main genres are action, adventure, comedy, ecchi and fantasy, with themes such as Kaiju, Female Protagonist, Medieval and Dissociative Identities.

On AniList, Luna Varga has an average score of 59%, an average score, and appears on 1,263 users' lists.

The Dunbas Empire tries to conquer the peaceful land of Rimbell. The three princesses are determined to resist the invaders, expecially the middle one, the tomboyish, sword-wielding Luna. After a magical escapade in the cellars of the castle, she finds herself embedded up to the hips in the head of a huge green reptile, the legendary Varga, and acting as its "brain". Even when in human form she has a reptilian tail. She has to fend off a very persistent giant invader and rescue her sister who has been kidnapped by a pterodactyl. (Source: AniDB)

Official synopsis from AniList.