Keru & Besu, also known as Ker and Beus in Japan are Ken Midori's two canine puppets that he uses to communicate with due to his shy personality. They first appeared in episode 2 of Beyblade Burst. Their names are a reference to the name of Ken's Beyblade, King Kerbeus, each of them having one of the syllables as its name. Keru and Besu each represent a different side of Ken's character.
Keru is the blue puppet and has pointed ears & teeth and an overall aggressive expression. He represents Ken's stronger, more passionate side. Ken often uses Keru whenever he wants to say something rude or make snarky comebacks. He also usually holds his bey, Kerbeus in Keru's mouth.