In the episode "Bad Egg", Magnus Finke realizes that Leyla's Dragon Diary contains much information about dragons, and therefore may contain information to get rid of dragons. He creates a tool to help him infiltrate the Rescue Riders' home - a hollow egg shaped container. He hides inside of it and leaves it in the woods, knowing that the Rescue Riders rescue abandoned dragon eggs. The Riders find the large egg and predictably bring it back to The Roost to care for it. During the night, Magnus emerges from the egg to search the premises for the Dragon Diary, but is seen by Cutter. Cutter decides to 'have fun' before telling the other Riders about Magnus. He slathers Slinkwing slime on the exit seam on the false egg, which acts as a glue so that Magnus cannot get out. He then rolls the false egg outside into the cold night. A mother Silver-tailed Ironclaw sees the egg alone in the cold weather and takes it back to her nest, thinking it is an abandoned egg of her species. Later, once the Riders figure out where the false egg and therefore Magnus went, they try to get it back from the Mama Ironclaw's nest. This proves difficult, as the mother dragon is very protective and thinks the egg is real. Ultimately Magnus, still inside the egg, rolls out of the nest. It bumps against a rock cliff face, and the now dry Slinkwing slime shatters. Magnus emerges and runs away, leaving the false egg on the cliff.
The false egg is made of metal and stands about as tall as a pre-teen human. It's metallic grey with lighter grey striations on it. There is a small hole with a latch which can be used to look through. The top of the egg is hinged on the inside and can open up.
Magnus Finke uses the hollow false egg to hide inside of for purposes of subterfuge. It is designed to mimic the appearance of a real dragon egg.