|Job:||Host of Anatomy Park, Military Veteran|
|First seen in:||Anatomy Park|
|Main voice actor:||Jess Harnell|
Ruben's past life is very vague. Aside from his hinted service within the United States Military, not much is known about Ruben. In his debut, he is seen appearing as a homeless man wearing a dirty Santa outfit. Rick himself states that giving Ruben's yearly "check-up" is his way of contributing to the homeless community.
Later in the episode he is seen naked on a table being operated on by Rick. It is revealed that he has been building an amusement park within the homeless man with the help of Dr. Bloom and several of his assistants. Rick comments, in regards to Ruben, "You don't agree to have a theme park built inside of you if your life is going well."
Ruben has animatronic exhibits inside a theater located in Anatomy Park, and he claims that his story "begins in the early 1990's at the start of the tech bubble."
He dies of tuberculosis in the episode with Morty and the others still stuck inside. In order to free Morty and everyone else, Rick grabs Ruben and brings him all the way to space with his car, he then enlarges Ruben so that Morty and Annie (everyone else having died) can escape out of the nipple hole and then blows up Ruben's corpse, causing it to rain blood onto all of North America.
Ruben is a dirty and grungy old homeless man who is most of the time, very drunk and tipsy. He has a very big gray beard which is long and frizzy and stanky. His sideburns are also very big and they poof out on the sides of his head. His eyes are glazed and usually stare off in different directions. He also has bags under his eyes and a little green puddle that is seen, dripping out of his mouth. He wears a Santa Claus outfit, complete with the Santa hat and red suit. The colors are very faded and the fabric is stained with a bunch of dirt and splotches.
Ruben is a homeless and unsuccessful old man whose life is so horrible, that he actually agreed to having a miniature theme park built inside of his body. Ruben drowns out his pain and misery by drinking tons of alcohol. Like Rick Sanchez, Ruben is most of the time very drunk and he belches a lot. However, Ruben is far more drunk than Rick is, as he can't even walk without the help of other people, have conversations with others, or form basic sentences. He instead just spews out random words every now and then. Although his life is absolutely nowhere now, he has apparently been involved with or at least witnessed huge events that happened a long time ago, such as World War II and the Korean war. He is probably a survivor of those wars who is very shaken up from the trauma of those wars, and he is currently so old, and so overdosed with alcohol, that all of this shaken behavior has been repressed into laziness and sloppiness and he no longer has a personality and barely has any control over his own mind anymore, making him the drunken, lunatic old fart he is now.
- It is hinted he served during both World War II and the Korean war hinted by the his sole words spoken in the episode; "Pearl Harbor" and "Korea".