The Michigan monster who murdered a pregnant teen and beheaded her boyfriend after arranging for a sex romp on Craigslist also had a twisted softer side – he dabbled in poetry, The ENQUIRER has learned.

Brady Oestrike, 31, committed suicide July 17 as cops were about to nab him for kidnapping and torturing 18-year-old Brooke Slocum, who was eight months pregnant.

Oestrike had beaten Slocum’s boyfriend to death five days earlier in a park where the pair had agreed to meet the sicko for a sleazy three-way for money.

Months before the savage crime, Oestrike had posted a poem, which he didn’t write, on his Facebook page. Titled “Thirteen at the Table,” it ends: “Crazy people don’t know they are crazy. I know I am crazy therefore I am not crazy, isn’t that crazy.”

Investigators are still searching for the head of Slocum’s boyfriend, Charles Oppenneer, 25. It was believed to be severed post-mortem by Oestrike, a gun-and-sword-loving electrical lineman who was into bondage, cops say.

The brutal crimes seem to be reflected in poems posted under the name “Brady Oestrike” on the website

One poem, titled “Darkness
Rises,” reads: “Pick the frozen flower, slice and sever the stem. Enjoy the soft sweet smell, its only your heart you condemn.”

Oestrike became a suspect after Slocum was reported missing and cops learned of the Craigslist hookup while searching her computer.

Oppenneer’s headless body was found July 16 in a Wyoming, Mich., park about 10 miles south of Grand Rapids.

Cops were outside Oestrike’s home waiting for a search warrant when he fled in his car, crashed it and shot himself in the head.

Slocum’s body was in the trunk. She’d been held captive by Oestrike for five days inside the home, and had been strangled to death.

Describing Oestrike’s home as a “hellish environment,” cops removed about 400 knives, guns, ammunition and electronics.

On his Facebook page, Oestrike posted photos of himself posing with swords in medieval clothes. Oestrike also “liked” Lady Gaga, Metallica and the TV show “Dexter.”

Social site as hunting ground

Medical student Philip Markoff became the best-known Craigslist killer when he was busted in April 2009 for murdering 26-year-old Julissa Brisman, whose body was found in a swanky Boston hotel. The 24-year-old creep also robbed two other women who’d advertised erotic services on Craigslist, but he committed suicide in jail in August 2010 before he went to trial.

Husband-and-wife team Miranda and Elytte Barbour are accused of using Craigslist to lure Troy LaFerrara, 42, to his death in Pennsylvania in November 2013. Elytte, 22, allegedly hid under a blanket in an SUV and popped up to strangle LaFerrara while Miranda, 19, stabbed him more than 20 times, cops say.

The first so-called Craigslist killer was Michael John Anderson, who was sentenced to life without parole in 2009 for killing Katherine Olson, 24, a Minneapolis student.