Callisto is an enormous bear that resides south of the Demonic Ruins, and is the only monster to drop the tyrannical ring. He attacks using melee. He can knock players back a few tiles, which renders them unable to move for a few seconds, as well as heal himself slightly. He is also able to perform a deadly shockwave attack that can hit up to 60.
Item Quantity Rarity GE market price Big bones 1 Always 262
Item Quantity Rarity GE market price Rune pickaxe 1 Common 18,715 Rune 2h sword 1 Uncommon 37,758 Dragon pickaxe 1 Rare (1/171) 5,614,513 Dragon 2h sword 1 Rare (1/256) 131,761 Tyrannical ring 1 Rare (1/512) 1,566,701
Item Quantity Rarity GE market price Soul rune 250 Uncommon 36,500 Death rune 300 Uncommon 60,900 Chaos rune 400 Uncommon 35,600 Blood rune 200 Uncommon 73,400
Item Quantity Rarity GE market price Uncut ruby 20 (noted) Uncommon  24,980 Uncut diamond 10 (noted) Uncommon  26,270 Coconut 60 (noted) Uncommon 112,200 Crushed nest 75 (noted) Uncommon 356,625 Magic logs 100 (noted) Uncommon 109,000 Limpwurt root 25 (noted) Uncommon 22,950 Red dragonhide 75 (noted) Uncommon 168,075 Mahogany logs 400 (noted) Uncommon 165,200 Uncut dragonstone 1 Rare (1/128) 13,080 Grimy toadflax 100 (noted) Rare (1/128) 158,800
Item Quantity Rarity GE market price Snapdragon seed 3 Uncommon 163,653 Ranarr seed 5 Uncommon 227,330 Yew seed 1 Rare (1/128) 68,162 Magic seed 1 Rare (1/128) 118,931 Palm tree seed 1 Rare (1/128) 39,781
Item Quantity Rarity GE market price Dark crab 8 Common  9,568 Super restore(4) 3 Common  29,838
Item Quantity Rarity GE market price Coins 12,000–20,000 Common Not sold Supercompost 100 (noted) Uncommon 45,600 Cannonball 250 Uncommon 43,000 Mysterious emblem 1 Uncommon (1/27.5) 68,122 Looting bag 1 Uncommon (1/30) Not sold Slayer's enchantment 1 Uncommon (1/30) 1,661 Clue scroll (elite) 1 Rare (1/100) Not sold Dark fishing bait 375 Rare (1/128) 1,500 Long bone 1 Rare (1/400) Not sold Callisto cub 1 Very rare (1/2,000) Not sold Curved bone 1 Very rare (1/5,000) Not sold
- Only dropped while on a slayer assignment given by Krystilia, unless the kill was done on the official Bounty Hunter world. Killing Callisto on the Bounty Hunter also increases the drop rate from 1/27.5 to 1/5.
- Only dropped while on a slayer assignment given by Krystilia.
- 1/50 if a Ring of wealth (i) is worn.
- Callisto is named after one of the Greek god Zeus' many lovers, who was turned into the constellation Ursa Major.
- Upon release, Callisto had a slightly worse drop table. In addition, players could exploit his low Magic by safespotting him with the trident of the seas behind a cluster of skeletons north of him. The cluster of skeletons have been removed and Callisto is now immune to Magic damage.
- Callisto is the name of one of Jupiter's moons.
- His examine text is a reference to Goldilocks and the Three Bears.
- There is a pile of bear droppings in the woods south of his spawn, with the examine text "Now you know." — a reference to the popular colloquialism, "Does a bear shit in the woods?", a rhetorical question in response to something where the answer is obviously yes.
Wilderness bosses and rewards