Rabbit's relatives are five hundred small white orphan rabbits whose exact relation to Rabbit remains unclear, though judging by their age and size they could be his nephews and nieces. They all come to visit Rabbit in The New Adventures of Winnie the Pooh episode "Party Poohper", in which Rabbit has trouble preparing a party for their arrival. His relatives arrive before the party is ready, so Rabbit asks Pooh, Piglet and Tigger to distract the bunnies while he finishes the preparations. Of course, things go wildly wrong with these three in charge.
Rabbit's relatives appear in the episode "Party Poohper". After Rabbit wakes up and follows his schedule he realizes he has to prepare for the party he invited his 500 relatives to. Rabbit organizes everyone to set up for the party. Winnie the Pooh bakes a cake, Tigger cleans, Gopher gets honey, while Piglet decorates. When the Bunnies come Rabbit realizes he is unprepared so he instructs Piglet to read to them. Piglet reads Jack and the Beanstalk, but it's a downer-ending version where the giant gobbled up everyone in the village. The bunnies scream and cry so loud, it shakes the whole house. Rabbit tells Pooh, Piglet and Tigger to take them for a walk. While the bunnies walk Rabbit bakes a different cake. The Bunnies walk all through the Hundred Acre Wood. While walking they fall into Gopher's house. Winnie the Pooh and co. Try to find them. Meanwhile, Gopher uses giant hands attached to long branches to get honey, but the bees chase him. He then tries dynamite which blows everybody out of Gopher's hole. Pooh, Piglet, Tigger and the Bunnies attend Rabbit's party. Rabbit realizes he doesn't need a schedule to have fun and everyone enjoys the party.
Rabbit also mentioned and visited his relatives off-screen in the episode, "Rabbit Takes a Holiday".