For this Fortnite challenge you'll need to dance on an Abductor or as a passenger on a Saucer.
The biggest difficulty in this challenge is to find a Saucer in the first place, but other than that you just need to bust an emote once there.
Where to find Saucers
This challenge is achievable on all flying saucers, whether they are Abductors or not. However, given the only Abductor is in the center of the map, it might be easier to land on a Saucer instead.
From the start of the game, the locations of the three Saucers can be seen on the map. Plan your dive from the Battle Bus accordingly!
Once you've landed on top of the Saucer, just break out a dance emote and the challenge should register as complete.
Be mindful of other players attempting the same challenge -- it's a good idea to try and rush the quest, or make sure you're armed first.