Meowy

Meowy (ニャーコ) is a cat previously owned by Power, now being owned by Denji after Power's demise.

Appearance
Meowy is a cat with black ears and a black spot (both brown in the anime) on the top of its head.

Power
Meowy was cared for by Power, they have a close relationship, as Meowy was one of power's only companions during her lonely times. Power even gets agitated when Meowy sleeps with Denji rather than her. They share a close bond together, and Power even wasn't afraid of sacrificing Denji to the Bat Devil so that she could have Meowy Back. Power and Meowy have very deep feelings for each other.

Denji

Meowy has been shown to sleep with Denji more frequently than power, indicating that Meowy feels affection towards Denji.

History
Meowy was brought under the care of Power, who originally intended to fatten up Meowy before eating. Power eventually become attached to Meowy and they were together for a long time until Meowy was captured by the Bat Devil, who promised that if a human were brought to him he would return Meowy.

Bat Devil arc
When Power returned with Denji, Meowy was eaten by the Bat Devil as punishment for bringing him blood that tasted disgusting. Meowy was freed along with Power after the defeat of the Bat Devil.

International Assassins arc
Recently it seems that Meowy frequently sleeps with Denji rather than Power which slightly annoyed her.

Gun Devil arc
Kishibe took care of Meowy temporarily when Aki, Power and Denji was going on a trip to Hokkaido for a couple of days. Meowy was then returned when they came back.

Later, upon hearing that the Gun Fiend is at the door, Denji quickly told Power to grab Meowy and run. The Gun Fiend later managed to catch up with Power and Meowy and attack them but luckily, Denji was able to protect both of them from the Gun Fiend, letting both Power and Meowy escaped safely.

Control Devil arc
Denji is now taking care of Meowy after Power's death.