This nine-card pack was issued and given out at various conventions and in orders during 2016, to commemorate Looney Labs' 20th birthday.
This is a self-contained set, so it can be added to any Fluxx, though note that it does contain chocolate, which is redundant with unthemed "regular" versions, so just take the duplicate out (or just let there be an abundance of Chocolate.)
The Party Favor pack contains:
Keepers: Chocolate, Cake, The Gift, Ice Cream
Goals: Chocolate Cake, Hot Fudge Sundae, Free Ice Cream!, Happy Birthday!, Cake and Ice Cream