The Dragon of Holding

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This strange magical hybrid, also known as a dragonbag, is thought to have resulted when a dragon was stuffed into a bag of holding, and then forgotten after the campaign was abandoned. Over time, the two merged to become the artifact known as the Dragon of Holding.

The item functions exactly as a regular bag of holding and even has a strap across the 'belly' that allows it to be carried over the shoulder. The bag is fully alive however, and as items must be taken in and out of the dragonbag's mouth, this can create difficulties if the creature is in a bad mood, or dislikes its current owner. 

The dragonbag also has two functioning wings, which makes the shoulder strap necessary as the creature may try to fly away in fear, boredom or in search of food.