The hot chocolate comes in a white cup with the drink's name imprinted on it in capitalized brownish-red text. There is also a brown stripe below the text.
Role in series
After SpongeBob's blabbering about the $5 Squidward gave him infuriates the latter, Squidward bangs on his table in anger, causing the hot chocolate he was drinking to fly up in the air and spill. Upon this, SpongeBob exclaims "Coffee rain!," only for Squidward to correct him, stating that it's hot chocolate, resulting in SpongeBob exclaiming "Chocolate rain!"
"Cave Dwelling Sponge"
SpongeBob takes it out of his backpack after Patrick gets his tongue stuck on the ice and pours it onto said ice to free him from it. Patrick suddenly reacts to the heat of the beverage by hitting his tongue with a rock. After SpongeBob decides it's "enough nature" for Patrick, he brings him by the tongue, then the heat of the beverage melts the ice and frees a cave sponge from within.