The Pet of Summer were obtained from combining Lush blossoms. Lush blossoms are won through playing Treasure Hunter, Woodcutting, or handing in a daily challenge. When combined with a Pet of Spring, Pet of Autumn, and Pet of Winter, a Pet of Seasons token is created. It cannot be talked with, nor does it have an emote. It cannot be reclaimed from Diango, Ianto, or any other way if lost. Also, it cannot be stored in a player-owned house Menagerie, but the Pet of Seasons can be stored there.
Concept art of the seasonal pets