The Klimpalooners are the secondary antagonists of the Phineas and Ferb episode The Klimpaloon Ultimatum. They are a team of of male synchronized swimmers working for their boss Mittington Random.
The Klimpalooners first appeared in the episode wearing giant parkas when Phineas, Ferb and the gang head to Random's Himalayan fortress to rescue the legendary creature Klimpaloon. Anticipating the kids' arrival, Random sets the Klimpalooners as guards around the fortress to capture the kids. Inside the lair, the kids are horrified to learn that there are several deformed Klimpaloon clones and that there is a device that would seemingly extract Kimpaloon's life force. Random explained to the kids that he and his men are planning to infuse Klimpaloon's life force into his latest swimwear line for a fortune. To that end, the Klimpalooners take off their parkas to reveal their new old-timey bathing suits before engaging into a musical number with Random to prove his point.
The kids are very disgusted by this revelation, so Ferb causes a power outage, which allowed the kids to free Klimpaloon from its restraints and run off with it. Random and the Klimpalooners tried to stop the kids, but they are too late as the kids finally escaped the fortress, thanks to Candace imitating the Klimpaloon's voice to throw them off the tracks. The kids head back to the 4th Annual Tri-State Area Music Show Awards (or Tristies for short) to prove Klimpaloon's existence to the public and expose Random's plot. An angry Random orders the Klimpalooners to go after the kids, but as they are about to exit the fortress, they start to shiver due to the extreme cold weather since they previously discarded their parkas during their musical number. Realizing that his men can't walk on the snow with their bathing suits on, an annoyed Random decides to go after the kids himself.
It is unknown what happened to the Klimpalooners after their boss was exposed of his plot, though it may be presumed that they became unemployed since Random lost his career and was briefly turned into a warthog (due to an elixir that Heinz Doofenshmirtz made for the award show).