
Here, I am JANITOR.
In former Soviet Union, I am physicist.
The Big Bang Theory Season 1, Episode 13

...and eat with the JANITOR.
The Big Bang Theory Season 4, Episode 22

Hans the JANITOR.
The Big Bang Theory Season 11, Episode 15

I have two PhDs yet somehow
I'm the JANITOR
The Big Bang Theory Season 7, Episode 11

So may I introduce the third-floor JANITOR,
the lady from the lunch room and...
The Big Bang Theory Season 1, Episode 13