Last night during dinner, I asked my oldest kid about kindergarten, and he told me they played "Couch potato tag" during P.E. (physical education)
I asked about the game dynamics and he said that when someone tags you, you become a couch potato. Then you need to wait until someone brings you healthy snacks (in the form of a green bean bag, so you have the "will" and energy to move from the couch again).
To keep the conversation going I asked him what a "couch potato" was, and his definition roughly was
Someone who is always in front of the TV and playing video games and eating tons of sugar
Which is pretty accurate. A "couch potato" is defined as
a person who spends little or no time exercising and a great deal of time watching television.
(idiomatic) A person who spends a lot of time sitting or lying down, often watching television, eating snacks or drinking alcohol. [from 1976]
To that definition I would add that in addition to alcohol, they could be drinking a lot of sugary drinks.
While a "couch potato" is a lazy person, "lazy" doesn't fully convey "couch potato", since "lazy" has a broader meaning. Also, you would not call "couch potato" to someone who sits for a long time reading (or coding! :-p). The "couch potato" represents that stereotype of the person who just wants to be in front of the TV, doing as little as possible, often eating unhealthily.
I don't know up to which point the literal translation into Spanish, "patata de sofá", would be appropriate.
What can be used in Spanish to convey "couch potato" - a person who spends a lot of time sitting in front of the TV, doing nothing, and trying to do as little as possible?