Warner Bros. is being sued by Nyan Cat and Keyboard Cat for the company's alleged unauthorized use of two felines that have achieved viral fame.
Clips of Nyan Cat and Keyboard Cat have each each spurred tens of millions of views since appearing online in 2011 and 2007 respectively.
The legal complaint alleged that the cats were used without permission in Scribblenauts, a series of games on the Nintendo DS and other platforms.
Court documents allege that Warner Bros. and developer 5th Cell "knowingly and intentionally infringed" both kitty claimants' ownership rights.
Says the legal complaint against WB and 5th Cell:
"Compounding their infringements, defendants have used 'Nyan Cat' and 'Keyboard Cat', even identifying them by name, to promote and market their games."
"All without plaintiffs' permission and without any compensation to plaintiffs."
Keyboard Cat was first partially created all the way back in 1984 when Charles Schmidt filmed his cat Fatso "playing" a electric keyboard.
More than two decades later, it was put to music and uploaded to YouTube in a clip called "Play Him Off, Keyboard Cat" ... in which he plays people off.
Not unlike how music comes on when producers want to wrap up an acceptance speech, web users use Keyboard Cat as way of mocking subjects in videos.
Nyan Cat, designed by Christopher Torres, is described in court documents as "a character with a cat's face and a body resembling a horizontal breakfast bar."
"With pink frosting sprinkled with light red dots, he flies across the screen, leaving a stream of exhaust in the form of a bright rainbow in its wake."
He was the fifth most-viewed YouTube clip in 2011.
Torres and Schmidt own copyrights and trademarks of the characters, and are seeking an injunction halting WB and 5th Cell from making money on them.