Madokajacks are large reptilian creatures that live in the 3rd Layer. They typically catch their prey while airborne, their arms and legs having evolved into wings that let it glide on the wind currents in the Great Fault. Their eyes are on stalks that stick out from the sides of their heads, and their jaws come together in huge pincers, giving them an insect-like appearance.
- In the anime, while traversing the 3rd layer, Reg and Riko stumbled upon an ancient ship buried in the side of the cliff. Upon investigation, it turned out to be a Madokajack's lair. In the manga however, the lair belonged to the same Scarlet Maw that attacked Riko before she found Reg.
- Its name was possibly taken from the anime Puella Magi Madoka Magica, as many noted its similarities with Made in Abyss.