Mystical Frosh Hat
Quest reward from Dressing With Class. Oh please sparkle or jump off my head and dance with some broom side kicks.
The 
Mystical Frosh Hat is a toy rewarded from the quest Dressing With Class, found deep within the Nar'thalas questline in Azsuna.
Guide awaiting review
Progress the Nar'thalas Questline
Work through the Nar'thalas questline in Azsuna until you reach the quest Dressing With Class. This quest is located deep within the questline, so you will need to complete the preceding quests to unlock it.
Complete Dressing With Class
Complete the quest Dressing With Class in Azsuna to receive the Mystical Frosh Hat as a reward. Note that accessing the lower level of Nar'thalas Academy requires the key obtained through the questline — the relevant treasures inside will not appear unless you are actively on the questline and use the key to enter.
Tips
Using the Mystical Frosh Hat transforms you into a ghost scholar of Nar'thalas Academy for 6 minutes, with a 6-minute cooldown. The disguise persists while mounted but is immediately removed if you take or deal any damage.
