
was for CUCKOO pills.
The Big Bang Theory Season 7, Episode 7

The newly hatched CUCKOO
eats all the food...
The Big Bang Theory Season 1, Episode 15

Oh, yeah. The Mr. Spock CUCKOO clock.
The Big Bang Theory Season 10, Episode 10

By that standard,
Penny is CUCKOO for Cocoa Puffs.
The Big Bang Theory Season 4, Episode 9

It's like the world's
fattest CUCKOO clock.
The Big Bang Theory Season 7, Episode 23