Meet 'Blobby? (or Steve the Slime)' (HT1)
[Media Type] Animation Film
[Movie Name] Hotel Transylvania (2012)
This blob monster is called 'Blobby' in Hotel Transylvania 2 and 3.
But there's no reference about it's name in Hotel Transylvania, the first film of this series released in 2012.
Instead, you can find it's original name, 'Steve the Slime', in Hotel Transylvania NDS Game, which is also released in 2012.