The yellow-rumped cacique was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae under the binomial name Parus cela.

The yellow-rumped cacique is a slim bird, with a long tail, blue eyes, and a pale yellow pointed bill.

It has mainly black plumage, apart from a bright yellow rump, tail base, lower belly and wing "epaulets".

The song of the male yellow-rumped cacique is a brilliant mixture of fluting notes with cackles, wheezes and sometimes mimicry.

This gregarious bird eats large insects (such as beetles, caterpillars, crickets, grasshoppers and katydids),[9][10] spiders[9] (such as orb-weavers),[10] nectar[9][10] and fruit (such as chupa-chupa and figs).

This species is apparently the paucar that, according to a folktale of Moyobamba, originated as a rumor-mongering boy who always wore black pants and a yellow jacket.