from Nightmare Before Christmas.
The Big Bang Theory Season 10, Episode 7
...and, eventually, it becomes
the so-called Christmas tree.
The Big Bang Theory Season 2, Episode 11
Marie, that was one time
at a Christmas party.
Breaking Bad Season 2, Episode 7
the broken Christmas tree
lights, so it was after that.
The Big Bang Theory Season 12, Episode 18
And then on Christmas morning,
The Big Bang Theory Season 5, Episode 4