Onyx Hook

The Onyx Hook is an item that appears in Mother. It is first received after beating the Fish miniboss in Magicant's Crystal Cavern. It can be used anywhere to teleport straight to Magicant. However, it can't be used to leave Magicant, which forces Ninten to go through the Crystal Cavern again to leave Magicant before he or Ana learns Teleport. It is considered a very useful item, despite being optional.