birds of a feather; villains of the same stripe
Idiomatic expression used to say that people who do bad things together are alike or equally guilty. Often carries a negative connotation. Literally 'raccoon dogs of the same hole'.
See also: 同じ穴のムジナ
Those two are birds of a feather.
The scammer and his lawyer were villains of the same stripe.
Standard kanji spelling for this idiomatic expression.
Katakana spelling of 狸, sometimes used for emphasis or in casual writing.
From the idea that raccoon dogs (狸) sharing the same den are alike in nature, extended metaphorically to people who collude in wrongdoing.