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 214
Item Quantity Rarity GE market price Rune pickaxe 1 Common 18,865 Rune 2h sword 1 Uncommon 37,949 Dragon pickaxe 1 Rare (1/171) 5,890,092 Dragon 2h sword 1 Rare (1/256) 132,470 Tyrannical ring 1 Rare (1/512) 1,810,976
Item Quantity Rarity GE market price Soul rune 250 Uncommon 36,000 Death rune 300 Uncommon 65,700 Chaos rune 400 Uncommon 36,800 Blood rune 200 Uncommon 72,600
Item Quantity Rarity GE market price Uncut ruby 20 (noted) Uncommon  27,640 Uncut diamond 10 (noted) Uncommon  27,840 Coconut 60 (noted) Uncommon 83,880 Crushed nest 75 (noted) Uncommon 257,475 Magic logs 100 (noted) Uncommon 104,100 Limpwurt root 25 (noted) Uncommon 20,475 Red dragonhide 75 (noted) Uncommon 173,775 Mahogany logs 400 (noted) Uncommon 110,000 Uncut dragonstone 1 Rare (1/128) 14,983 Grimy toadflax 100 (noted) Rare (1/128) 164,200
Item Quantity Rarity GE market price Snapdragon seed 3 Uncommon 148,548 Ranarr seed 5 Uncommon 211,670 Yew seed 1 Rare (1/128) 77,512 Magic seed 1 Rare (1/128) 114,477 Palm tree seed 1 Rare (1/128) 34,958
Item Quantity Rarity GE market price Dark crab 8 Common  10,360 Super restore(4) 3 Common  28,008
Item Quantity Rarity GE market price Coins 12,000–20,000 Common Not sold Supercompost 100 (noted) Uncommon 39,100 Cannonball 250 Uncommon 37,750 Mysterious emblem 1 Uncommon (1/27.5) 74,902 Looting bag 1 Uncommon (1/30) Not sold Slayer's enchantment 1 Uncommon (1/30) 1,402 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