Heronicus is a character in The Flip Flop Show who lives in Flipside in the houses behind Saffron's restaurant. He is a retired explorer who "knows much about other lands", with certain smells bringing back memories. After each chapter a different smell brings back a memory of the world Bleu has just visited.

It is mentioned in Flopside that he had a partner who lived in the house parallel to Heronicus', whose "game ended tragically". The treasure maps that they collected can be bought from Flamm in the underground of Flopside.

Heronicus also appears briefly at the beginning of Chapter 6, fleeing from the Sammer Guys.