Candy coral is a variant of coral that causes one's tongue to swell. It appears in the comic A Swell Time.
Candy corals are groups of multi-colored, jagged, sparkly rocks. However, despite their name and appearance, they should not be licked, as they contain a poison that makes the consumer's tongue swell up for a few hours. Due to this, a sign stating "Don't lick the candy coral" has been placed near the coral to deter people from doing so.
Role in comic
While walking, SpongeBob and Patrick spot a cluster of candy coral. SpongeBob notices a sign that warns of the coral, and he and Patrick decide to just observe the coral. However, the temptation of the candy coral is too much, and the two lick the coral, causing their tongues to swell up.