Don’t go berserk putting together this 1,000-piece puzzle full of hippos from the inimitable Sandra Boynton!

These famous hippos, stars of the wild Hippos Go Berserk book, have been partying nonstop since 1977. Surprisingly, it hasn’t aged them a bit—they are as enthusiastic and unruly as ever. And now it gets even berserker: hippos have overflowed the book, invited more hippos, and now star in their very own puzzle. The way they explain it is this: It’s their job to go berserk. It’s your job to try to restore order. Good luck with that.