A vintage trailer is parked on a gigantic boulder that emerges out of a murky pond. Balanced on top is a small tugboat inhabited by a tentacled monster. A European goldfinch enjoys the view from the deck, unaware of two loaded missiles right behind. Meanwhile, a snail sips on a strawberry daiquiri after enjoying a light swim.

This painting, titled Table for One, is part of “Freakazoid,” a show of recent works by Adam O’Day opening at Longstreet Gallery in Eastham this week.

Not all of O’Day’s work is so outlandish. He is perhaps best known for his paintings of Boston cityscapes rendered in vibrant colors. Last year, he had a show of grungy still lifes — sinks, Purell bottles, egg cartons — also at Longstreet Gallery.

Born in Tennessee, O’Day lived “all over”: Pennsylvania, Michigan, and Atlanta, where he went to high school. “My parents didn’t have cable because they were super religious,” he says. Instead, he fell in love with comic books, especially Calvin and Hobbes. “He was a sick watercolorist,” remarks O’Day.

He went to the Art Institute of Boston, but didn’t become a full-time artist right away. First, he worked as a designer for a printing company, then as a structural engineer for the Navy. O’Day’s first inkling that he could “make it” was when his cityscapes started selling. He attributes their success to “familiarity” — something that can’t be said about the paintings in “Freakazoid.”

He’s been a full-time artist for nine years and lives in Abington, Mass. O’Day also performs as a drummer and vocalist in the heavy metal band Mollusk, currently working on its third album, called Glass Eye Full of Meth. In addition to showing at Longstreet, he is represented by Woodman Shimko Gallery in Provincetown.

The “Freakazoid” series, started in December, was inspired, in part, by the pandemic. O’Day kept hearing about Mother Nature taking over during lockdown — “the fricking dolphins are back in Venice,” he says — and began imagining a bizarre scenario: “What if humans were gone and there were just animals and aliens?” Many of the paintings take place, more or less, on the Cape.

The series was also inspired by O’Day’s two daughters, ages three and six. The title, “Freakazoid,” was dreamt up by Penny, the older. “They ask me questions like, ‘Daddy, what’s inside an iceberg?’ It has helped me be creative in a new way,” he says. “It’s nice to look through my kids’ eyes, almost.”

The answer to “what’s inside an iceberg?” turns out to be “a queen.” Ice Queen shows a woman’s features superimposed on a floating block of ice — flecks of flesh-colored paint reflected in the dark water. It is reminiscent of René Magritte.

“I wanted to use my representational work as something in my arsenal along with a crazy narrative,” says O’Day. His skill is evident in the way he paints complex surfaces like gems, Mylar balloons, and disco balls. (It turns out that aliens like shiny things.) This is even more impressive, considering he doesn’t use any reference material.

O’Day says that Hieronymus Bosch is “one of my all-time favorites,” pointing out that the 16th-century Netherlandish artist completed only 20 paintings in his lifetime. “He was doing surrealism before it was a thing.” The works in “Freakazoid” similarly invite close examination.

In Penguin Island, a crew of emperor penguins commanding a steampunk ship is encamped on an iceberg. A mutant one-eyed narwhal looks on, concerned.

Freaktown looks “as if you just piled P’town up into a big ball,” says O’Day. Layers of Cape Cod houses, all floating on a pier, are connected by Escheresque staircases. If you look closer, you realize the shadows are squid-like aliens and giant rabbits. It has a folk art feeling to it.

O’Day’s series is playful, but also a little dark. The unspoken narrative is that humans have gone extinct — presumably of a deadly virus. It’s partly in honor of O’Day’s father, who died in 2019. O’Day wanted to honor him in a joyful way, sort of like Day of the Dead, he says.

“These are not challenging paintings to look at,” admits O’Day. It is “a more personal series to myself.” He appreciates having a gallery that will support this kind of work. “I don’t even care if nobody buys these — because I love doing it.”

Freak Show

The event: “Freakazoid,” a show of works by Adam O’Day; paired with “Fresh Cuts,” works by Vanessa Irzyk

The time: Thursday, June 17 to June 27; Thursday through Sunday, 11 a.m. to 5 p.m.; reception Saturday, June 19, 5 to 8 p.m.

The place: Longstreet Gallery, 4730B Route 6 in Eastham

The cost: Free