YO! CATS was one of three Halloween models released by Hummingbird in 1990. The other two models were YO! BONES, and YO! JACK. The three-piece yo-yo was made out of hard rock maple and in a Classic configuration. This series was painted in mostly Halloween-themed colors such as black, neon orange, and neon yellow. The Halloween Series was a smaller release for Hummingbird in terms of number produced. Today, the three models in this Halloween series are hard to find.