Henry King's Exequy is probably the creepiest poem in English. But very few people understand it enough to realise what is actually being said.
Aleister Crowley is pretty challenging until you get used to him. Here is
Sleeping in Carthage
The month of thirst is ended. From the lips
That hide their blushes in the golden wood
A fervent fountain amorously slips,
The dainty rivers of thy luscious blood;
Red streams of sweet nepenthe that eclipse
The milder nectar that the gods hold good--
How my dry throat, held hard between thy hips,
Shall drain the moon-wrought flow of womanhood!
Divinest token of sterility,
Strange barren fountain blushing from the womb,
Like to an echo of Augustan gloom
When all men drank this wine; it maddens me
With yearnings after new divinity,
Prize of thy draught, some where beyond the tomb.