Theory:

An Anagram is a word or phrase which is formed by rearranging the letters of another word or phrase.
Example:
1. Lemon - Melon
2. Great - Grate
3. Star - Rats
An antigram is an anagram that gives the opposite meaning to the original word or phrase.
Example:
1. United - Untied
2. Earliest - Arise late
3. Harmfulness - Harmless fun
Anagrams from the lesson "A Story of Self Sacrifice and Bravery":
  1.  Seat – East
  2.  Alert – Alter
  3.  Leapt – Plate
  4.  Garden – Danger
  5.  Elbow – Below
  6.  Listen – Silent
  7.  Present – Serpent
  8.  Time – Item
  9.  Heart – Earth
  10.  Hose – Shoe