And the answer was ELEPHANT.
The Big Bang Theory Season 4, Episode 24
You're like those ELEPHANT seal pups...
The Big Bang Theory Season 8, Episode 23
And I will return to New Delhi in triumph
atop a bejeweled white ELEPHANT.
The Big Bang Theory Season 6, Episode 20
If I had an ELEPHANT
named Topsy,
The Big Bang Theory Season 11, Episode 8
What was he, a bad ELEPHANT
who died and went to hell?
The Big Bang Theory Season 5, Episode 10