It first aired on February 23, 2018.
The Futon Critic
Dr. Fox's robot helpers go on strike, so Unikitty and Puppycorn volunteer to be her research assistants. As the mission grows dangerous, Dr. Fox is forced to choose between the scientific breakthrough or seeing her friends.
The episode starts with a young Dr. Fox playing in her room. She notices a comet called Tasty's Comet hurtling towards Earth and observes it.
It cuts to present day where Dr. Fox is amazed to see its return. With its surface unknown, Dr. Fox vows to get a sample of its surface. She enlists Unikitty and Puppycorn as the pilots (who mistake the role for space pirates.) She reveals to the future pilots her rocket Mark I. She explains to them their objective to travel to Tasty's Comet and get a sample.
She has a short imagination of getting a science reward as Unikitty and Puppycorn cheer for her.
Dr. Fox theorizes Tasty's Comet is actually a giant gumball. She then trains them for the dangers of space, only for them to fail. Unikitty says they aren't cut out to be pilots. Dr. Fox sings a song to them about how science must continue and the breakthroughs they'll make.
With Unikitty and Puppycorn still unsure, Dr. Fox convinces them by letting them have the leftover samples. She then gives them more tests of space. She says they'll reach the comet no matter what. Dr. Fox says they're ready for liftoff.
Dr. Fox has another imagination of being called the smartest in science and she couldn't have done it without her pilots.
Mark initiates launch sequence. (After doing a lunch sequence for not paying attention) In space, Dr. Fox has Mark initiate autopilot, but he didn't install one. (Thinking he had to go on a diet) Unikitty is then forced to steer herself. Dr. Fox says they can make it to the comet.
She has another imagination of being 1st in science, with Unikitty and Puppycorn injured as they congratulate her.
Unikitty and Puppycorn are almost sucked out of the ship from a meteor. Another meteor gets stuck in the gears. Unikitty begs Mark to do something, but he sets his course to crash into the meteor. Dr. Fox says they might still get it.
Dr. Fox has yet another imagination where she is the President of Science, but Unikitty and Puppycorn are not there and presumably dead.
Dr. Fox has them launch the escape pod to survive and says that science must stop. They are launched back to Earth.
However, the comet explodes, and samples land all around the kingdom. They all cheer, and the episode ends just before they are crushed by a chunk of the meteor.
For a full transcript of "Lab Cat", click here.