The transmutation school of magic consisted of spells that changed the physical properties of some creature, thing, or condition. The school was previously known as alteration. A wizard who specialized in transmutation was known as a transmuter.
Transmutation spells included bull's strength, eagle's splendor, and the various polymorph spells.
Alter Self
Animal Shapes
Animate Objects
Awaken
Barkskin
Blink
Control Water
Control Weather
Create or Destroy Water
Darkvision
Disintegrate
Druidcraft
Enhance Ability
Enlarge/Reduce
Etherealness
Expeditious Retreat
Fabricate
Feather Fall
Flesh to Stone
Fly
Gaseous Form
Giant Insect
Glibness
Goodberry
Haste
Heat Metal
Jump
Knock
Levitate
Longstrider
Magic Weapon
Meld into Stone
Mending
Message
Move Earth
Passwall
Plant Growth
Polymorph
Prestidigitation
Purify Food and Drink
Regenerate
Reincarnate
Reverse Gravity
Rope Trick
Sequester
Shapechange
Shillelagh
Slow
Speak with Plants
Spider Climb
Spike Growth
Stone Shape
Telekinesis
Thaumaturgy
Time Stop
True Polymorph
Water Breathing
Water Walk
Wind Walk