Scare 20 students using a ghost character

Turn the sound down to 0 and music off in the options menu whilst in the library

Defeat the mountain troll, using Quirrell

Defeat 20 spiders with Ron

Defeat 10 enemies with a Muggle character

Hide in a barrel as Snape

Complete all the LEGO Builder tutorial levels.

Buy every version of Voldemort (Quirrell/Tom Riddle/Voldemort)

Destroy 50 Devil's Snare plants

Rescue all students in peril

Buy the entire Weasley family

Collect all of the house crests in Year 3