In the Marvel Cinematic Universe, we are introduced to Knowhere in the first Guardians of the Galaxy. Knowhere is out on the edge of space and along with several questionably 'legal' establishments, it is also home to The Collector and his collection.
Among his collection is a curious, living item - a dog in a space suit. This is Cosmo the Spacedog and we have no idea why he's part of the collection or if he has the same abilities as his comic counterpart, but in the comics he's a powerful telepath and a member of the Guardians of the Galaxy.
Where The Collector and his Tivan group founded and own Knowhere in the MCU, Cosmo is the administrator and head of security of Knowhere in the comics. He is also a founding member of the Knowhere Corps, which came along later in Knowhere's timeline.