Blob Alien

A background creature glimpsed in the churn of the show's alien-of-the-week universe, the Blob Alien exists mostly to fill out a scene — some gelatinous, unnamed presence reacting to whatever chaos Rick and Morty have wandered into, more texture than character.

Justin Roiland's gift for tossing off a fully formed voice for a creature that gets maybe one line is part of what makes the show's universe feel infinite and lived-in; even a blob gets a distinct, slightly gross, oddly specific vocal personality before vanishing.