Walmart has Toymendous Oopsie Cushion 2 Pack - Fart Pad Prank Toys for Children Ages 3+ for $2.72. Shipping is usually free to Walmart+ members or on orders over $35.

About this product:

Featuring cute cat and dog designs, the Oopsie Cushion 2 Pack, also called a Whoopie Cushion or Whoopy Cushion, is ready for some fun pranks. A classic toy, these fart cushions make a funny gift for kids and adults of all ages. You're sure to get laughs all around! Just inflate the rubber cushion with air, place on a friend's chair and wait for them to sit down. As they sit, the room will be filled with the sound of someone cutting loose followed by lots of laughter!