It is most-likely Toe-Fur was one of Exquisite's pet sloths present during the RainWing Royal Challenge, either one of the ones on Exquisite, or one of the slothes that choked Jambu to stop him from winning the treetop race.
When Moonwatcher pulls aside a leaf to reveal a tendril of delicate white-blue flowers to show Winter that not everything in the rainforest was flamboyant, he spots Toe-Fur climbing in a branch far overhead. Winter leaps to his feet and shoots into the air, aiming his claws at the sloth's belly to kill it and eat it. Moon and Kinkajou both give shrieks of protest, then something slams into Winter's side and knocks him into a tree. He lashes out at the red enemy dragon, instinctivly thinking it is a SkyWing, with his tail, then his claws, but it whisks under and away from him and swoops up to the sloth and grabs it before vanishing entirely.
Winter roars furiously, and Qibli tries to calm him down. As Winter begins to explain about the SkyWing, he realizes that it must have been a RainWing, as only a RainWing could vanish like that. The RainWing, later shown to be Exquisite, materializes in front of them, angrily declaring that Toe-Fur is no dragon's lunch and that one of the NightWings had already eaten one of her sloths.