One piñata, full of candy. Every whack does damage. Whoever breaks it takes half, and everyone who hit it splits most of the rest.
A whack costs 10,000 $PINATA. Half is burned, and half goes into the candy.
Damage is 1 to 100, and 1 whack in 20 is a crit for triple. It's rolled from the hash of the next block, so nobody knows it in advance, you included.
Whoever lands the breaking whack takes 50% of the candy. 40% is split among everyone who hit it that round, by damage. 10% goes to the next piñata.
A reserve drips into the candy all the time, at 1/30 of the reserve per day. A piñata nobody touches is a piñata worth more.