Black Kikimora
From Puyo Nexus Wiki
Black Kikimora is the shadow of Kikimora that first appeared in Kikimora's Clean Up and is her complete opposite in personality, and likes to lay a trap usually with her mop.
In Puyo Puyo Box you fight her in stage 21 after Minotauros. One could hypothesize she is related to the doppelgangers, but this is highly untrue.
