Buy RS3 Undead dragonhide
Undead dragonhide is a tough hide that peeled away from an undead dragon in RuneScape 3. It drops from the Zemouregal and Vorkath loot chests. The item is tradeable and noteable, so it is easy to move and sell.
You can turn the hide into undead dragon leather at a tanner like Sbott. You can also use the Make Leather spell at level 83 Magic. The spell works on 28 hides at once and uses Astral, Body, and Fire runes.
The leather is used to craft undead dragonhide armour. This is ranged tank armour that needs level 75 Crafting to make and level 75 Defence to wear. A full set uses nine hides and gives 918 Crafting XP. The set has five pieces: coif, body, chaps, vambraces, and boots. It has the same armour bonus as dinosaurhide armour, but it does not degrade and it needs a lower Crafting level. You can also upgrade it with Vorkath spikes to make Dracolich armour.
The hide can be disassembled too. It gives Simple parts most of the time and has a small chance of Living components. This makes it useful for both crafters and Invention training.