Charles H. Spurgeon on Psalms 55:21

A feigned friend is much like a crocodile who, when he smiles, poisons; and when he weepeth, devoureth; or the hyaena, having the voice of a man and the mind of a wolf, speaking like a friend and devouring like a fiend; or the flattering sirens that sweetly sing the sailor's wreck; or the fowler's pipe that pleasantly playeth the bird's death; or the bee, who carrieth honey in her mouth and a sting in her tail; or the box tree, whose leaves are always green, but the seeds poison. So his countenance is friendly and his words pleasant, but his intent dangerous, and his deeds unwholesome.

His fetch is to flatter, to catch what he can;

His purpose obtained, a fig for his man. —L. Wright, 1616.