Yuigadokusonmaru

Yuigadokusonmaru (唯我独尊丸, Yuigadokusonmaru), often called just Dokusonmaru (独尊丸, Dokusonmaru) for short, is Kasuka Heiwajima's cat who is mentioned in passing a few times in the light novels and appears in the anime.

Adabashi Arc
Yuigadokusonmaru is sent to live with Anri Sonohara to protect him from Kisuke Adabashi before he runs away after Kisuke attacks Anri and he is saved by Mikado Ryuugamine.

Etymology

 * The name Yuigadokusonmaru means "conceit/self-conceit, narcissism/narcism, vainglory, egotism/egoism, vanity, pride, selfishness, assurance, self-love" (唯我独尊) (yuigadokuson) and "round, circle, pills, purity, suffix for ship names, complete" (丸) (maru).
 * His nickname Dokusonmaru means "self-respect" (独尊) (dokuson) and "round, circle, pills, purity, suffix for ship names, complete" (丸) (maru).