Megan Fox, 40, transforms into deadly siren in very revealing look as she shares chilling message: 'The sea was the grave'

 Megan Fox channeled a deadly siren in a sizzling Halloween look.

The actress, 40, transformed into a gothic mermaid in a series of sultry snaps shared to her Instagram on Saturday. 

The photos showed her plunging into dark waters under the glow of the moon while wearing a shimmering silver bra and a sheer grey mermaid tail. 

Completing the jaw-dropping look, her hands featured eerie webbed fingers tipped with dramatically long, shimmering dark nails.

Her face was adorned with glittering gems and she wore iridescent silver and violet glam. 

Fox - whose ex Machine Gun Kelly, 36, has moved on with Dakota Johnson, 37 - also issued an ominous warning about her siren song, writing in the caption: 'the song was the trap, and the sea was the grave.'

Her sizzling display comes following reports that she is unfazed by MGK's new relationship with Johnson.

The star, who shares 18-month-old daughter Saga Blade Fox-Baker with the musician, 36, has no plans to revisit their past relationship as she's focused on other priorities in her life. 

Fox is 'unbothered' that her ex has moved on, and she is not interested in getting involved in his love life, sources told TMZ. 

Insiders also told the outlet that Fox is currently single and plans to keep it that way as she focuses on being a hands-on mother and making money.

This comes just shortly after Fox launched her exclusive content page on Subs.com and after her new ad campaign for telehealth company Ro was released. 

The former couple, who called off their engagement in November 2024 and welcomed their child together in March 2025, reportedly no longer have any kind of relationship outside of co-parenting.

The Daily Mail has reached out to Fox's representatives for comment. 

'MGK and Megan are done and only communicate about their daughter and co-parenting logistics,' a source told Us Weekly in late September. 'They both know they have toxic tendencies and it's much better this way.' 

The source also said that the rapper 'will always love Megan and have a soft spot for her' but said he 'gave up pursuing a romantic relationship with her several months ago.' 

Fox and MGK, born Colson Baker, welcomed their daughter in March 2025, just four months after their relationship reportedly ended in November 2024 following claims the actress discovered he had been communicating with other women. 

She is also mother to three sons - Noah, 14, Bodhi, 12, and Journey, 10 - from her past marriage to Brian Austin Green. MGK is also father to 17-year-old daughter Casie, whom he shares with ex Emma Cannon.

MGK and Fox had a turbulent, on-and-off relationship that lasted for about four and a half years. 

In January of this year, a source told People: 'Their relationship at this point is just about co-parenting. Megan is focused on her kids and the baby and just getting settled into this new chapter. That's genuinely her priority.

'Megan's very happy with how he's stepped up for both her and the baby. While they still have separate homes, they spend a lot of time together as a family. They're putting the baby first, and it's brought them closer in many ways.'

Added the source, 'Things are great now. He's amazing with the baby and she very much enjoys spending time with him.'

Just last week, Johnson was spotted waiting for MGK outside of a recording studio in Los Angeles.

Recently, insiders also dished on Johnson 'having the best sex of her life' with him.

On Friday, a source told the Daily Mail that Johnson has told friends things are heating up between her and Machine Gun Kelly, stemming from time they spent with one another at the July 4 wedding between Taylor Swift and Travis Kelce.

'She has told friends that they have great sexual chemistry and it's the best sex she has ever had, she calls it "fireworks,"' the source said. 

An insider close to the actress also told the Daily Mail that they are talking about their future and introducing him to her family.

'They have agreed they would have the most beautiful babies, and she wants kids, so while they look like a very unlikely couple at first glance, I do think they want the same thing in the end: a family.' 

'They actually have a pretty firm foundation because they started out as friends and got to know each other well before ever having becoming romantic, so they know each other very well,' they added. 

Johnson spent six years with English Coldplay frontman Chris Martin, who shares his children Apple, 22, and Moses, 20, with his ex-wife Gwyneth Paltrow.

She was subsequently linked to American indie singer Role Model, and a decade ago was involved with Matthew Hitt, the Welsh lead singer of the Drowners.