In the Florida Keys, it’s common for locals and savvy visitors to greet the news of some particularly offbeat happening by grinning and murmuring, “Only in the Keys.”

The four-word phrase is a standard response by people hearing about everything from a costume contest for pets to mermaids attending a local music festival (FYI, these are both actual things).

Lower Keys mermaid

“Mermaid” Sarah Brunner pretends to play a starfish guitar during a past Underwater Music Festival in the Florida Keys National Marine Sanctuary. (Photo by Bob Care, Florida Keys News Bureau)

Along with examples of wonderful wackiness, there are many intriguing events and experiences that can be enjoyed “only in the Keys” … like the four suggestions here.

ONE: Take a selfie with Betsy. Lobster lovers can snap a selfie with a REALLY BIG example of the species — believed to be the world’s largest lobster sculpture — outside the Rain Barrel Village in Islamorada. Known as Betsy, the 30-foot-tall, 40-foot-long replica of a Florida Keys spiny lobster stands in front of the open-air arts enclave to greet visitors.

The 12-legged crustacean was crafted in the 1980s by an area artist named Richard Blaze, and was a much-photographed icon in another Upper Keys location before relocating to the Rain Barrel in 2009. These days, the whimsically named Betsy stars in countless selfies taken by passersby who can’t resist stopping to check out her charms.

TWO: Attend a music festival — underwater. Each July, several hundred divers and snorkelers explore a gorgeous section of the continental United States’ only coral barrier reef during a sub-sea concert in Lower Keys waters.

The Lower Keys Underwater Music Festival spotlights coral reef protection and environmentally responsible diving. Staged by local radio station US1 104.1 FM, it takes place at Looe Key Reef, part of the Florida Keys National Marine Sanctuary about 6 miles south of Big Pine Key.

Participants swim among Looe Key’s vivid marine life and coral formations while listening to music broadcast by the radio station — and piped underwater via speakers suspended beneath boats above the reef.

Winter Star Party Florida Keys

Steve Miller of Bristol, Illinois, peers through his telescope during a past Winter Star Party. Begun in 1984, the event is organized by the Southern Cross Astronomical Society. (Photo by Dan Baker, Florida Keys News Bureau)

Some divers might even spot costumed “mermaids” beneath the waves (yes, those mermaids noted earlier) pretending to play quirky musical instruments. The 2023 festival is coming up Saturday, July 8.

THREE: Get “starstruck” in the Lower Keys. Spotting major stars in the Lower Keys doesn’t usually mean sighting Tom Cruise, Zendaya or even a random Kardashian.

Instead, when 600 or so “starstruck” people gather for the annual Winter Star Party, their goal is to observe southern constellations, comets and celestial objects in the region’s clear night skies.

The Lower Keys, by the way, are virtually the only place in the continental U.S. where these wonders can be seen — primarily because the southern location, “steady” skies and relative absence of large-scale artificial lighting at night provide world-class viewing conditions.

Held each February, the annual star party draws professional and amateur astronomers and astro-imagers from around the globe. The 2024 gathering is scheduled Feb. 5-11.

FOUR: Attend a costume contest — for pets. Each October, normally rational people all over the Florida Keys get busy constructing costumes for their cats, dogs, parrots, potbellied pigs, rabbits and other domestic animal companions.

cat in costume Key West Pet Masquerade

Dr. Anesa Ahamad, left, displays her “vampire cat” Pixel with Andrew Balthazar, right, at a previous Fantasy Fest Pet Masquerade. The annual costume contest is a highlight of Key West’s 10-day Fantasy Fest celebration. (Photo by Rob O’Neal, Florida Keys News Bureau)

What’s behind this strange phenomenon? A wacky annual costume competition known as the Pet Masquerade — a highlight of Key West’s 10-day Fantasy Fest costuming and masking celebration. Entries typically range from simple pet-and-person duos to multi-member animal-and-human ensembles attempting to perform musical numbers.

Among the most memorable past participants were a “vampire cat” with its own cat-sized coffin (accompanied by human cohorts dressed like Dracula), and a group that performed a musical salute to Alfred Hitchcock’s film “The Birds” — with a blonde-wigged Borzoi hound portraying “Birds” actress Tippi Hedren.

And few spectators can forget the rescued racing greyhound whose owners dressed her as seductive songstress Tina Turner. The hapless dog stood stoically while her eight-member human “back-up band” proceeded to mangle a Turner classic. The 2023 Pet Masquerade is planned for Wednesday, Oct. 25.

Let’s face it — whether you’re in Islamorada, the Lower Keys, Key West or elsewhere in the subtropical Florida Keys, the prevailing eccentricity is one of the area’s greatest appeals. So start planning a trip now to discover why the most fun-filled vacation experiences are found “only in the Keys.”