Perfect Storms (2013)

S4E3 The Lost Mattress

Mr. Krabs is grumbling about back pain, prompting SpongeBob and Patrick to purchase a new mattress for him. Meanwhile, Squidward attempts to claim credit for their thoughtful gesture. Once they deliver the new mattress to Mr. Krabs, they discover that he had hidden his money in the old one. While Mr. Krabs is at the hospital, SpongeBob, Patrick, and Squidward scramble to locate the old mattress before he returns.