The Festival of Yay is a Seasonal Monsters elemental type in My Singing Monsters. It is manifested in Yool, Rare Yool and Epic Yool on Cold Island and its Mirror Island. These monsters are only available during the Yay season or sometimes out-of-season during special events such as the Anniversary Month Celebration which allows breeding. The Yay season is normally celebrated within the month of December, however, the times vary from year to year. Check out the Special Occasions page for the dates and times of the past Yay seasons.
Although the Yay element appears on News articles when the Yool, Rare Yool, or Epic Yool is available for breeding/purchase, it does not appear under the Info section of the monsters' profile like other confirmed elements. Thus, it is unknown if Seasonal elements are canon within the game.
The list of monsters that are affiliated with the Yay element are listed below.