what biblical character does the creature compare himself to? what character does he think he ought to be?

Adam

The encounter between Victor and his creature is charged with Biblical allusions: like Adam, the creature has been forsaken by his creator. For him, Frankenstein occupies the position of the Christian god. The creature is also subtly aligned with the figure of Satan, or the devil: like him, he is a "fallen angel," grown brute and vicious in the absence of his god.

The Creature compares and identifies more to Lucifer than he does Adam. Hence why he reads Paradise Lost and connects with it.