"MUCUS plug" again.
The Big Bang Theory Season 11, Episode 16
Can you go to the kitchen and get me
the turkey baster labeled, "Mucus"?
The Big Bang Theory Season 1, Episode 11
Oh, I watched a video
of the hagfish producing MUCUS,
The Big Bang Theory Season 9, Episode 9
Has your MUCUS plug popped out?
The Big Bang Theory Season 11, Episode 16