In "Lost Mattress" Squidward threatens to kill SpongeBob when he says "i am going to mur-" before saying "i mean help you find it myself"
SpongeBob can be heard singing the end credits theme as he skips to Mr. Krabs' office.
Normally Mr. Krabs sleeps in a hammock, but he sleeps on a bed with a mattress here.
First appearance of Patrick in Season 4.