Giant rock crabs are massive versions of the weaker Rock crab. They lie in wait for prey, disguised as large boulders. When approached, they attack, unless they have become tolerant, in which case they remain as "boulders" - attempting to cast a spell on them gives the message "You can't attack this NPC."
Giant rock crabs are only initially aggressive if they are approached while dormant. Once they are moving and the targeted player is out of range, they stop being aggressive and will ignore players that don't attack them. They eventually become dormant boulders again after a while if they are not attacked.
Locations[]
- In Waterbirth Island Dungeon (a partner or a pet rock required to open the door).
Strategy[]
The giant rock crab is one of few monsters in RuneScape that will retreat from battle when they become critically wounded. This can be troublesome, as they are found in a single-way combat area. This can be prevented by attacking them while their back is turned to a nearby wall, so that they move away from the player and back up into the wall. If they move too far away, the player will follow them and risk being attacked by another rock crab. There are several protruding sections of the walls in the area that can be used as safespots which are ideal as the crabs' main weakness is magic.
Drops[]
100%[]
Item Quantity Rarity GE market price 
Bones 1 Always 89
Runes/Talismans[]
Item Quantity Rarity GE market price
Water rune 1–39 Uncommon 4–156
Earth rune 2–37 Uncommon 8–148
Air talisman 1 Rare 92
Mind talisman 1 Rare 3,875
Fire talisman 1 Rare 4,924
Cosmic talisman 1 Rare 784
Body talisman 1 Rare 1,028
Water talisman 1 Rare 171
Earth talisman 1 Rare 310
Weaponry/Armour[]
Item Quantity Rarity GE market price
Steel platebody 1 Uncommon 901
Black claws 1 Uncommon 407
Black platebody 1 Uncommon 3,696
Mithril axe 1 Uncommon 75
Rock-shell gloves 1 Uncommon 489
Rock-shell boots 1 Uncommon 275
Black warhammer 1 Rare 332
Adamant longsword 1 Rare 1,644
Adamant warhammer 1 Rare 2,204
Seeds[]
Item Quantity Rarity GE market price
Poison ivy seed 1 Uncommon 18
Belladonna seed 1 Uncommon 57
Guam seed 1 Uncommon 9
Marrentill seed 1 Uncommon 5
Tarromin seed 1 Uncommon 10
Harralander seed 1 Uncommon 31
Toadflax seed 1 Rare 795
Ranarr seed 1 Rare 45,466
Irit seed 1 Rare 47
Avantoe seed 1 Rare 1,675
Snapdragon seed 1 Rare 54,551
Cadantine seed 1 Rare 1,034
Lantadyme seed 1 Rare 2,358
Dwarf weed seed 1 Very rare 423
Torstol seed 1 Very rare 58,385
Herbs[]
Item Quantity Rarity GE market price
Grimy guam leaf 1 Uncommon 15
Grimy marrentill 1 Uncommon 13
Grimy tarromin 1 Uncommon 132
Grimy harralander 1 Uncommon 674
Grimy ranarr weed 1 Rare 7,640
Grimy irit leaf 1 Rare 775
Grimy avantoe 1 Rare 1,814
Grimy kwuarm 1 Rare 1,165
Grimy cadantine 1 Rare 1,312
Grimy lantadyme 1 Rare 1,391
Grimy dwarf weed 1 Rare 448
Other[]
Item Quantity Rarity GE market price
Coins 27; 28; 42; 70; 137 Common Not sold
Raw lobster 1 Common 210
Raw bass 1 Common 457
Tinderbox 1 Common 62
Rock-shell splinter 1 Uncommon (1/64) 24,845
Rock-shell chunk 1 Uncommon (1/64) 12,280
Rock-shell shard 1 Uncommon (1/64) 21,332
Casket 1 Rare 731
Clue scroll (medium) 1 Very rare Not sold
Gem drop table
In addition to the drops above, this monster has access to the gem drop table.
Show/hide gem drop table Item Quantity Rarity GE market price
Uncut sapphire 1 Rare 455
Uncut emerald 1 Rare 679
Uncut ruby 1 Rare 1,249
Nature talisman 1 Very rare 744
Uncut diamond 1 Very rare 2,627
Rune javelin 5 Very rare 875
Loop half of key 1 Very rare 10,307
Tooth half of key 1 Very rare 10,840
Rune spear 1 Very rare 11,933
Shield left half 1 Very rare 65,697
Dragon spear 1 Very rare 37,226
