Marketing description from Lego.
Starting December 1st, there’s a door to open each day with a surprise Harry Potter toy hidden inside. Includes popular characters, Hedwig the owl, and iconic mini-build items from the Harry Potter movies. Each minifigure comes with a 2x4 display stand plate in a different color. There’s even a board game to play once all the doors have been opened.
There are mini-builds of the Goblet of Fire, Triwizard Cup, Room of Requirements, Hall of Phrophecies, Knight Bus, Pensieve, The Burrows, Hogwarts Express and other iconic builds.
The first 3 toys make a scene from the first movie, the next 3 days make a scene from the second movie, and so on.
Advent includes 8 minifigures:
Note: LEGO site states 7 minifigures but doesn't count Severus Snape for some reason - there are 8 minifigures in the advent.