The astronauts decided to take a plush toy of the beloved character from Disney+ series The Mandalorian, having revealed the little guy as their companion in a live stream from their journey.
But now the gang have arrived at their destination, with video footage showing them entering the International Space Station for their mission.
Astronaut Soichi Noguchi can be seen entering the hatch with the toy in his hand, before releasing him and letting him float around.
Along with Noguchi, an astronaut with Japan's space agency, Baby Yoda will be keeping NASA's Michael Hopkins, Victor Glover and Shannon Walker company for the next six months.
When they arrived, the new arrivals shared hugs with NASA astronaut Kate Rubins and Russia's Sergey Ryzhikov and Sergey Kud-Sverchkov, who were already onboard after arriving at the ISS last month on a Russian Soyuz spacecraft.
Keeping with tradition, the NASA and JAXA crew took the toy with them as their 'gravity indicator' when they launched from the Kennedy Space Center on 15 November.
They kept Baby Yoda a top secret until they reached zero-gravity and their fifth passenger popped out.
It's not the first time SpaceX astronauts have decided to take a little mascot with them, as earlier this year NASA's Bob Behnken and Doug Hurley took a sparkly toy dinosaur along with them for the ride.
The two astronauts both have sons who love dinosaurs and let them choose one of their toys to go to space with them.
Tremor, a sparkly apatosaurus, was the lucky winner, with Behnken saying during a tour of the capsule: "That was a super cool thing for us to get a chance to do for both of our sons who I hope are super excited to see their toys floating around with us on board.
"I'm sure they would rather be here, given the opportunity, but hopefully they're proud of this as well."
The mission earlier this year was a way for SpaceX to show it can safely take astronauts to the International Space Station, and get them back in one piece.
It was the final step on SpaceX's journey to being certified by NASA's Commercial Crew programme for regular flights carrying astronauts to the International Space Station.
Sunday's launch, meanwhile, was the first NASA-certified commercial human spacecraft system in history.Featured Image Credit: NASA/SpaceX