What they are: Permanent, interchangeable, unequippable school-based transformations received every 10 levels or so.
How they work: Every 10 levels, you get a quest from your teacher that gives a Guise as a reward. They will be different from the Crowns Shop ones so as not to interfere with Crowns income.
Fire: Fire Elf Pathfinder: Level 10 Fire Elemental: Level 20 Phoenix (Human-sized): Level 30 Helephant (Human-sized) Level 40 Draconian: Level 50 Efreet (Human-sized, lower half of body is a red tornado): Level 60 Grand Drake (Draconian General): Level 70
Ice: Red Gobbler (Gobbler Gorger): Level 10 Arctic Ninja Pig: Level 20 Pegasus (Pure white, human-sized): Level 30 Colossus: Level 40 Frost Giant (Human-sized): Level 50 Arctic Angel (Snow angel rider, human-sized, on foot): Level 60 Mammotaur (A blue man with a Wooly Mammoth's head, human-sized): Level 70
Life:
Pixie: Level 10 Seraph: Level 20 Dryad/Forest Spirit (latter is male Dryad, both are human-sized): Level 30 Centaur/Amazonian Centaur (latter is a female centaur wearing plate armor): Level 40 Treant: Level 50 Forest Lord: Level 60 Gnome/Gnome Princess (both are human-sized): Level 70
Myth:
Troll: Level 10
Cyclops: Level 20
Minotaur: Level 30
Dragonspyrian Soldier: Level 40
Golem (Rock Colosus, human-sized): Level 50
Medusa/Gorgon Knight (latter is a male Medusa in gold plate armor, both are human-sized): Level 60
Basiliskian (Humanoid Basilisk, stands on two legs, human-sized): Level 70
Vampire (Humanoid form and size, resembles Count Dracula with the head from the Vampire spell): Level 30
Wraith: Level 40
Scarecrow: Level 50
Morgantine Warrior: Level 60
Katzenstein's Monster: Level 70
Balance:
Puppet (Haunted Minion, solid form): Level 10 Krokotillian: Level 20 Green Mander: Level 30 Sand Colossus: Level 40 Judgement/Truth Spirit (latter is a male judgement, both are human sized): Level 50 Crab Knight: Level 60 Ra (human-sized): Level 70