The line “How sharper than a serpent’s tooth it is to have a thankless child!” is spoken by King Lear in William Shakespeare’s play King Lear (Act 1, Scene 4).

Who said it?

  • The quote is delivered by the stage character Lear , the aging king of Britain in King Lear.
  • The phrase comes from Shakespeare’s tragedy King Lear , where Lear laments the ingratitude of his daughter Goneril.

What the quote means

  • Lear is saying that a child’s ingratitude hurts worse than the bite of a serpent, emphasizing emotional pain over physical pain.
  • In context, he feels betrayed after giving away his power and receiving disrespect and coldness in return from his daughter.

Fun extra: where it appears today

  • The line is widely quoted in literature guides, quote collections, and crosswords; for example, crossword clue sites identify “Lear” as the character who says it.
  • It has inspired later titles, such as the Star Trek: The Animated Series episode “How Sharper Than a Serpent’s Tooth,” which directly credits King Lear for its title.

TL;DR: The person who says “how sharper than a serpent’s tooth” is King Lear , in William Shakespeare’s King Lear.