The makers of "The Big Bang Theory" are being sued over a lullaby that's been featured on the hit comedy.
"Warm Kitty" or "Soft Kitty" as the song is also known, has been sung several times on the show whenever the character Sheldon needs comforting.
But the heirs to an American teacher who wrote a poem about a "soft kitty" are now seeking damages for breaching copyright, including for the spin-off merchandise featuring the lyrics.
