The situation surrounding Duncan's death, Lady Macbeth's guilt, and Macbeth's insanity are all examples of dramatic irony because we have witnessed Macbeth and Lady Macbeth plan out and commit the act of murder.
Stephano and Trinculo were referred to Caliban as a monster because he was a deformed man.
Caliban is an antagonist in the play by William Shakespeare entitled 'The Tempest.'
The author, in dramatis personae, described Caliban as a <em>'savage and deformed slave.' </em>Caliban is a son of witch, Sycorax. Caliban is a deformed slave with a half body of a man and half of an animal.
By Prosperous's statement which states Caliban as disproportioned in manner as disproportioned in his shape signifies that Caliban is not just ugly in his appearance but also in his character.
So, when Stephano and Trinculo is refering to Caliban as a monster they are referring to his deformed body of half-man and half-animal.