The Big Bang Theory: 10 Best Characters Who Only Appeared In One Episode

Episode: "The Property Division Collision" (Season 10, Episode 10)

Sheldon is moving in with his girlfriend, which means that he and Leonard must decide who gets to keep the mutually-owned items in their apartment that Leonard now shares with Penny. Naturally, Sheldon and Leonard are unable to agree. This leads to a tit-for-tat which culminates in Sheldon allowing an eccentric drifter named Theodore (Christopher Lloyd) to move into his old room, much to Leonard and Penny's displeasure.

Christopher Lloyd just gets more funny with age, like a humorous wine. He's a joy to watch here and is able to elevate even Theodore's most ordinary lines (such as "Hey. How you doing?") into utter hilarity.

What makes him especially memorable is just how odd and mysterious Theodore's character is. Almost nothing is revealed about him except his blood type and his self-confessed proficiency at rubbing against things, but we just know that there's an epic life story to be explored.

We would've loved to see Theodore in more episodes (or even a spin-off) but his brief appearance here is pleasing enough.