Daikokuten

Caster is one of four Udon Servants created by Leonardo da Vinci with the intention of keeping the story of the comic busy. Found by Jeanne and Nitocris while still an udon larva, they decide to feed it to recovering Gudako in lieu of having to gather ascension materials to raise it. Caster later manifests to take care of Gudako despite having been eaten, constantly giving her rice balls. This causes Jeanne and Nitocris to begin to compete with Caster for their Master's attention.

While the given the True Name of Daikokuten, one of the Seven Lucky Gods, the Servant is not the deity himself. They are the servants of the god summoned in the capacity of "women of servitude," but they have a different true form.

(Source: TYPE-MOON Wiki)