He is the "Dormouse" in the Alice in the Country of Hearts manga.
Pierce Villiers is created by Quin Rose and illustrated by Soumei Hoshino. His character is loosely based on the Dormouse from Lewis Carrol's work, Alice in Wonderland. He first appears in Alice in the Country of Hearts volume 4.
He first appears when Alice sees him getting pursued by Boris. Pierce tries to run away from Boris who has a water gun.