The knight his thrillant spear again assayed
  In his brass-plated body to emboss,
  And three men's strength unto the stroke he laid;
  Wherewith the stiff beam quaked, as afraid,
  And glancing from his scaly neck, did glide
  Close under his left wing, then broad displayed.
  The piercing steel there wrought a wound full wide,
That with the uncouth smart the Monster loudly cried.

[...]

The steely head stuck fast still in his flesh,
  Till with his cruel claws he snatched the wood,
  And quite a sunder broke. Forth flowed fresh
  A gushing river of black gory blood,
  That drowned all the land, whereon he stood;
  The stream thereof would drive a water-mill.

Book I, Canto XI