Tidal serum

The Tidal Serum is a trinket that could previously be found in Prize Boxes and Daycare Gift Boxes, and is now permanently available in the Gold Boutique. It can be attached to any horse, but it has a special effect when attached to eggs. It will freeze them; in this state, they do not take up a foaling stall, and they cannot gain any more levels. This effect is reversed if the Tidal Serum is taken away.