"Mr. Grunty" (プチグソさん) is a Baby Grunty owned by Hotaru. It was found by her after its original owner abandoned it when it became sick. Shugo and Hotaru managed to find a cure for it, and as a result it became permanently attached to them. Mr. Grunty spends most of his time on Hotaru's head, and is known for his insatiable appetite. When Shugo found himself hunted by Kamui and the Cobalt Knights, Zefie used her powers to turn Mr. Grunty into a unique Longhorn Grunty capable of flying away. However the effect was only temporary, and Mr. Grunty returned to his normal state shortly afterwards.