W. D. Gaster was the Royal Scientist before Alphys, responsible for creating the CORE and said to have disappeared. W. D. Gaster does not have an officially known form, but there are several rooms and unused assets found in Waterfall that point to what he may have looked like. Characters such as the River Person and Gaster's Followers hint at his existence. In particular, Gaster's Followers relay various explanations as to what happened to Gaster. he can also speak wingdings and normal english. 