Mystic Robe Bottoms
Mystic Robe Bottoms is an item for the Legs slot that needs Magic level 55, picked by the game as recommended gear for Magic. 
Mystic Mage (combat level 60) drops it 2.0% of the time, so expect about 50 kills for one. It sells for 4,500 gp.
Compare all Legs gear · see recommended gear
Obtained from
Monster drops — Mystic Mage — 2.0%
Related items
- Magic legs upgrades: before it,
Wizard Robe Bottoms (needs Magic 25); next, 
Air Mage Legs (needs Magic 60). - Same family:
Apprentice Robe Bottoms, 
Penny's Robe Bottoms. - Also dropped by Mystic Mage:
Threeli's Attuned Shard, 
Chaos Rune, 
Big Bones, 
Death Rune, 
Mystic Staff, 
Mystic Hat, 
Mystic Robe Top, 
Mystic Gloves.