Animal Breeder 4 is a breeding game developed and published by J-Wing for the Game Boy Color platform, exclusively released in Japan. Two years after Animal Breeder 3, this game comes out with some new or modified features: this time, there is no need to win every prize in each tournament, but to complete a sort of Pokédex instead, in order to beat the game; the number of animal species has been greatly reduced (from 322 to 128, compared to Animal Breeder 3); the introduction of money, allowing the player to buy animals and items; minigames prior to Animal Breeder 3 are now only available through training, etc.