Aaahh!!! Real Monsters S04 E19 Spy vs. Monster

The Academy shuts down when a human spy is discovered inside. From Ickis' hiding place, he realises he has dropped a drawing of The Gromble in the hallway. The spy picks it up and accidentally drops his own secret document. Ickis, Krumm and Oblina use the paper to track down spy headquarters and arrange for a transfer of the documents.