The term "glooshy" is frequently associated with specific animation techniques used to make characters appear more elastic or viscous. If this is a specific video link you received, it is highly likely part of a series of fan-funded animations where "Final" denotes the completed version of a project that was previously in "WIP" (Work in Progress) status.
: Beyond the aesthetic, these works often subvert Pokémon tropes—such as the relationship between trainers and their Pokémon—using humor that ranges from slapstick to dark or suggestive. Production Quality pretty thicc pokemon parody final glooshy link