The term 'zakki' is used to refer to the demons of lower rank. After Masahiro exorcized Ban Ban, they became his informants and tell him of any strange or unusual events they come across. 

They normally refer to Masahiro as Seimei's grandson, much to Masahiro's chagrin. 

In the anime, the Zakki are usually represented by three demons; a lizard with three eyes, a yellow skinned gremlin and a pink, round ball.