TEXT:  
  Arcane Traditions 
  The study of wizardry is ancient, stretching back to the 
  earliest mortal discoveries of magic. It is firmly established 
  in the worlds of D&D, with various traditions dedicated to 
  its complex study. The most common arcane traditions in 
  the multiverse revolve around the schools of magic. 
  Wizards through the ages have cataloged thousands of 
  spells, grouping them into categories called schools. In 
  some places, these traditions are literally schools; a wizard 
  might study at the School of Illusion while another studies 
  across town at the School of Enchantment. In other 
  institutions, the schools are more like academic 
  departments, with rival faculties competing for students and 
  funding. Even wizards who train apprentices in the solitude 
  of their own towers use the division of magic into schools 
  as a learning device, since the spells of each school require 
  mastery of different techniques. 
  School of Transmogrification 
  Perhaps none of the arcane spellcasters mighty powers is as 
  versatile, useful, or spectacular as the ability to change into 
  something else entirely. The School of Transmogrification 
  specializes in just that – altering one’s own body as needed 
  with polymorph, and other shapechanging transmutations. 
  Natural Adaptation 
  At 2nd level, you add the spell alter self to your spellbook, 
  if it is not there already. You can cast this spell without 
  expending a spell slot. After doing so, you can’t do so 
  again until you finish a short or long rest, though you can 
  still cast it normally using an available spell slot. 
  Favored Shapes 
  At 6th level, choose three beasts as your favored shapes. A 
  favored shape is a specific kind of creature whose form you 
  can assume by means of the polymorph spell. Whenever 
  you gain a level in this class, you can replace one of your 
  favored shapes with another beast of your choice. 
       You have advantage on Constitution saving throws 
  made to maintain concentration while in one of your 
  favored shapes. 
       You choose an additional favored shape at 10th, 14th, 
  and 20th level. Your favored shapes chosen or replaced at 
  17th level and beyond can be any creature, not just beasts. 
   
   
   
  Natural Transmogrification 
  At 6th level, you add the spell polymorph to your 
  spellbook, if it is not there already. You can cast this spell 
  without expending a spell slot. When you do so, you can 
  target only yourself and only to become one of your 
  favored shapes. Once you cast polymorph in this way, you 
  can’t do so again until you finish a short or long rest, 
  though you can still cast it normally using an available spell 
  slot. 
  Reflexive Change 
  At 10th level, when you are attacked or a creature causes 
  you to make a saving throw, you can use your reaction to 
  cast polymorph (expending a spell slot for a prepared 
  polymorph spell or using the Natural Transmogrification 
  feature) targeting yourself and only into one of your 
  favored shapes. Beginning at 17th level, you can instead 
  cast true polymorph in this way. 
       After using this feature, you must finish a short or long 
  rest before using it again. 
  Infinite Variety 
  At 14th level, you gain the ability to create imaginary 
  forms when casting polymorph, true polymorph, and 
  shapechange on yourself. To create an imaginary form, 
  choose one of your favored shapes as a base form. You 
  then choose a single aspect of a second monster whose 
  form you can assume with the spell being cast and add it to 
  the first creature. Available options include the following. 
    ● Replace the base form’s Armor Class with that of the 
  second form. 
    ● Add the second form’s movement modes (i.e. swim 
  speed, climb speed, burrow speed, fly speed). 
    ● Add one of the second form’s natural attacks if the base 
  form doesn’t already have that attack. 
    ● Add one of the second form’s damage resistances, 
  damage immunities, or senses. 
    ● Add one of the second form’s special qualities, besides 
  Spellcasting or Shapechanger. 
    ● Replace one of the base form’s physical ability scores, 
  if both forms are of the same size category. 
  For example, if the base form was a Tyrannosaurus Rex, 
  and the second form was a Giant Owl, you could add the 
  fly speed of 60 feet to the Tyrannosaurus Rex, making it a 
  winged T-Rex. If the first form was a Giant Scorpion, and 
  the second a Giant Octopus, you could add the Octopus’s 
  tentacle attack to the Giant Scorpion, grappling enemies 
  from afar, then clawing and stinging them. 
  
SOURCE: textdata/thevault/Dungeons & Dragons [multi]/5th Edition (5e)/3rd Party/Mage Hand Press/School of Transmogrification.pdf