— Warm milk, "InSPONGEiac"
The warm milk is first shown in several mugs earlier in the episode. In its sentient appearance on the billboard later in the episode, it is just a singular glass of milk which has a face made up of milk. It also appears to be able to make its face disappear and reappear, seen when SpongeBob runs past the billboard.
Role in episode
SpongeBob drinks several mugs of warm milk in order to help him go to sleep. Unfortunately as SpongeBob goes to bed, all the warm milk he drank pours out of his holes.
The warm milk appears later in the episode, now in a sentient form, it asks why SpongeBob had to drink them. SpongeBob says that he only drank the warm milk because it was delicious, with it then being shown that he was only talking to a billboard for cold refreshing milk. As SpongeBob sighs in relief and runs past the billboard, the warm milk becomes sentient again, asking why SpongeBob had to drink them in an even more devastated way.
- Despite being warm milk, the sentient form shown on the billboard is for cold milk.
- It's likely the sentient warm milk on the billboard is actually the spirit of the warm milk that SpongeBob drank earlier in the episode, now possessing a billboard.
- This is evident in the fact that the warm milk asks why SpongeBob had to drink them, implying that the warm milk was killed from being consumed by SpongeBob. This also confirms that this is the same warm milk that SpongeBob drank earlier in the episode.