
...ever to be stuffed
into his own CELLO case.
The Big Bang Theory Season 4, Episode 18

Little snarky there,
Cello Lessons.
The Big Bang Theory Season 5, Episode 12

Leonard, I didn't know
you played the CELLO.
The Big Bang Theory Season 1, Episode 5

Leonard, you'll play your CELLO.
The Big Bang Theory Season 2, Episode 12

When I broke up with Penny,
I got back into my CELLO...
The Big Bang Theory Season 4, Episode 3