Wrinklers are leech-like creatures that appear during the Grandmapocalypse in the game Cookie Clicker. They have a 0.0003% chance to spawn per frame, and the chances increase as you go through each stage of the Grandmapocalypse. When a Wrinkler attaches to your cookie, you gain a 5% debuff to your Cookie Per Second, and this stacks as multiple Wrinklers attach to it (up to a maximum of 10, thus 50% debuff) . However, they store all the cookies that they have leeched, and when popped, they return 1.1 times the cookies they leeched. In the long run, although they appear to be a debuff, they actually return more than lost, since none of the cookies they leech are actually destroyed. Therefore, it is beneficial to leave them attached to your cookie for a long time to get loads of cookies from them. To remove a Wrinkler, simply click on it (multiple times) and it will pop.