This is a congruent conflation of “look who’s talking” and “that’s the pot calling the kettle black”, both referring to pointing out hypocritical behavior. The best and most common malaphors are mixtures of phrases that have the same or similar meaning.
This is a mash up of “the pot calling the kettle black” and “cat calls”. Let’s also throw in black cats for good measure, and maybe “cattle calls”? Pot and cat are three letter words ending in t, another possible cause for confusion. Thanks to Kimberly for providing this gem.