If Sheldon's testosterone dipped,
he'd become a BUTTERFLY.
The Big Bang Theory Season 9, Episode 21
I'm a BUTTERFLY.
The Big Bang Theory Season 12, Episode 6
I ate a BUTTERFLY.
The Big Bang Theory Season 5, Episode 18
...I have burst forth
as the world's smartest BUTTERFLY.
The Big Bang Theory Season 8, Episode 1
"Look, Mommy-- a BUTTERFLY."
The Big Bang Theory Season 5, Episode 1