It has light yellow frosting as the base color of the cake, with light blue rims at the top and bottom. The text "Sorry about the Scabies" is transcribed on the top of the cake with pastel frosting. Next to the writing is a pink flower imprint and a few dark green leaves. The cake is shown on a pink plate.
Role in episode
SpongeBob buys this cake for Patrick's birthday. He then asks the bakery if she could give him another cake that reads "Happy Birthday," but she refuses and says it is the only cake she has available. SpongeBob purchases it anyway since he is running out of time.
Scabies is a skin disease in humans where mites burrow into the skin and cause a rash that is similar to a disease called mange in animals with fur. In this case, scabies is an STI to those in Bikini Bottom, like it would be in the real world. More information about this disease can be read here.
According to Casey Alexander's Twitter feed, the scabies joke was based on his experience with it at the age of 10.
"I'm allowed to make the scabies joke 'cause it comes from personal experience. My 10 year old self was delighted w/ that one."