|Release date||22 May 2012 (Update)|
|XP per kill||661 (and 218.1 experience)|
|Always drops||Big bones|
|Examine text||The final stage of a grotworm before its metamorphosis.|
|Assigned by||Turael or Spria, Mazchna or Achtryn, Chaeldar, Sumona, Vannaka, Duradel or Lapalok, Kuradal, Morvran|
Mature grotworms are monsters that can be found on the bottom level of the Grotworm Lair. They have slow, but accurate and hard-hitting magic and melee attacks. However, magic attacks are only used on players outside of melee range, similar to monsters such as metal dragons and cockroach soldiers. It is possible to safespot them using the pillars if you stand far enough back from them. Lower-level players are recommended to bring high healing food such as monkfish or sharks. Ranged/magic would require Protect from Magic/Deflect Magic if using safe spots. The magic attack has a short range, so flashing your prayer when out of its range can help conserve prayer points. Despite their ranged weakness, a player with 70+ melee stats should have little trouble killing them efficiently, even without the use of prayer.
Using high level ranged gear such as Armadyl and using a bunyip will reduce the need for prayer potions/flasks. The occasional Shark drops will reduce the need for food, and ranged gear will mean little damage from the mature grotworms' magic attack while ranging.
If a player tries to set up a cannon within the Grotworm Lair, they will receive a message saying: "The damp air would prevent your cannon operating." This does not prevent hand cannons from working, however.
Some players may find it useful to bring runes to cast High Level Alchemy on the items dropped by the grotworms, as adamant and rune equipment are common drops. The profit of using this spell on some of these items is greater than banking and selling them.
Item Quantity Rarity GE market price Big bones 1 Always 646
- Represents 90% confidence range, based on a sample of 6,660 kills.
1 charm is dropped at a time.
- Please add to the log (only if 50 or more creatures killed).
Weapons and ArmourEdit
Item Quantity Rarity GE market price Adamant chainbody 1 Common 2,311 Adamant sq shield 1 Common 1,710 Rune dagger 1 Common 4,250 Rune helm 1 Common 10,647 Rune mace 1 Common 7,792 Rune longsword 1 Common 18,323 Royal cape 1 Rare 305
Item Quantity Rarity GE market price Grimy guam 1 Uncommon 564 Grimy marrentill 1 Uncommon 125 Grimy tarromin 1 Uncommon 44 Grimy harralander 1 Uncommon 130 Grimy ranarr 1 Rare 3,126 Grimy irit 1 Rare 2,548 Grimy avantoe 1 Rare 4,412 Grimy kwuarm 1 Rare 3,511 Grimy cadantine 1 Very rare 2,307 Grimy lantadyme 1 Very rare 9,004 Grimy dwarf weed 1 Very rare 9,373
Item Quantity Rarity GE market price Fellstalk seed  2 Common 1,626 Belladonna seed 1 Rare 59 Cactus seed 1 Rare 34 Poison ivy seed 1 Rare 9 Toadflax seed 1 Uncommon 1,351 Irit seed 1 Rare 233 Avantoe seed 1 Rare 3,021 Kwuarm seed 1 Rare 217 Snapdragon seed 1 Very rare 2,539 Cadantine seed 1 Very rare 799 Lantadyme seed 1 Very rare 38,773 Dwarf weed seed 1 Very rare 40,848 Torstol seed 1 Very rare 36,153
- ^ No anagogic ort is dropped along this drop.
Item Quantity Rarity GE market price Flax 50 (noted) Common 3,950 Runite ore 1 Common 10,670 Adamantite ore 3 (noted) Common 5,880 Royal dragonhide 1 Uncommon 5,747
Item Quantity Rarity GE market price Coins 5,000 Common Not sold Saradomin brew (2) 1 Common 699 Shark 2 Common 2,230 Blood rune 20 Common 7,960 Long bone 1 Rare Not sold Curved bone 1 Rare Not sold Clue scroll (hard) 1 Rare Not sold Spirit sapphire 1 Rare Not sold Spirit emerald 1 Rare Not sold Spirit ruby 1 Rare Not sold Court summons 1 Very rare Not sold Starved ancient effigy 1 Very rare Not sold
Rare drop table dropsEdit
- This monster has access to the rare drop table.
The ring of wealth is not required to access the table.
Show/hide rare drop table Item Quantity Rarity GE Market Price Coins 200–350;3,000 Common Not sold Uncut sapphire 1 Common 1,255 Uncut emerald 1 Common 2,751 Uncut ruby 1 Common 3,546 Uncut diamond 1 Uncommon 5,843 Loop half of a key 1 Uncommon 32,996 Tooth half of a key 1 Uncommon 42,167 Uncut dragonstone 1 Rare 15,502 Dragonstone 1 Rare 9,984 Dragon dagger 1 Uncommon 16,452 Rune battleaxe 1 Rare 24,131 Rune javelin 5 Rare 840 Adamant javelin 20 Very rare 1,280 Rune 2h sword 1 Very rare 37,356 Rune spear 1 Very rare 11,419 Dragon spear 1 Very rare 36,478 Battlestaff 200 (noted) Rare 1,529,400 Rune sq shield 1 Very rare 21,988 Rune kiteshield 1 Very rare 31,603 Shield left half 1 Very rare 63,247 Dragon helm 1 Very rare 59,600 Adamant bolts 200 Uncommon 13,800 Onyx bolts 150 Rare 1,272,600 Rune arrow 150 Rare 22,650 Vecna skull 1 Very rare 107,406 Water talisman 1 Uncommon 16,022 Earth talisman 25–35 (noted) Uncommon 134,875–188,825 Fire talisman 25–35 (noted) Uncommon 131,350–183,890 Chaos talisman 1 Uncommon 973 Nature talisman 1 Uncommon 424 Pure essence 1,000–1,500 (noted) Uncommon 15,000–22,500 Nature rune 60–80 Rare 17,280–23,040 Soul rune 20 Rare 3,780 Law rune 45 Rare 21,735 Death rune 50 Rare 13,150 Blood rune 50 Rare 19,900 Raw swordfish 125–250 (noted) Uncommon 51,375–102,750 Raw shark 250 (noted) Uncommon 327,500 Big bones 150–180 (noted) Uncommon 96,900–116,280 Coal 550–700 (noted) Uncommon 132,550–168,700 Adamantite ore 150–250 (noted) Uncommon 294,000–490,000 Silver ore 100 (noted) Rare 8,800 Runite ore 100 (noted) Rare 1,067,000 Rune bar 1 Common 13,906 Rune bar 50 (noted) Very rare 695,300 Clean toadflax 35–45 (noted) Uncommon 140,630–180,810 Clean snapdragon 30–35 (noted) Uncommon 150,900–176,050 Clean torstol 16–34 (noted) Uncommon 133,536–283,764 Snapdragon seed 1 Common 2,539 Torstol seed 1 Uncommon 36,153 Watermelon seed 3 Uncommon 6,519 Magic seed 3–7 Rare 414,126–966,294 Palm tree seed 10 Rare 1,137,860 Yew logs 450–550 (noted) Rare 171,900–210,100 Crystal triskelion fragment 1 1 Very rare Not sold Crystal triskelion fragment 2 1 Very rare Not sold Crystal triskelion fragment 3 1 Very rare Not sold Brawling gloves (Melee) 1 Very rare Not sold Brawling gloves (Magic) 1 Very rare Not sold Brawling gloves (Ranged) 1 Very rare Not sold Brawling gloves (Agility) 1 Very rare Not sold Brawling gloves (Cooking) 1 Very rare Not sold Brawling gloves (FM) 1 Very rare Not sold Brawling gloves (Fishing) 1 Very rare Not sold Brawling gloves (Hunter) 1 Very rare Not sold Brawling gloves (Mining) 1 Very rare Not sold Brawling gloves (Prayer) 1 Very rare Not sold Brawling gloves (Smithing) 1 Very rare Not sold Brawling gloves (Thieving) 1 Very rare Not sold Brawling gloves (WC) 1 Very rare Not sold
- Universal drops are dropped by nearly every monster outside of Daemonheim.
- These drops are dropped alongside main drops.
Item Quantity Rarity GE market price Key token 1 Rare Not sold
- When these creatures were first released, they did not drop items from the rare drop table, but did after the Queen Black Dragon update.
- The word 'grotworm' means caveworm in Dutch.
- Their examine text hints towards the possibility of the existence of a stronger grotworm based creature, although likely not an actual worm as "metamorphosis" implies, but none were released with them.
- On 17 June 2013, these monsters received a massive power increase. Their lifepoints more than tripled, their accuracy was increased greatly, and their damage output was made substantially higher. This considerably decreased the amount of botting and people in general coming to the grotworms for money. They were level 120 with 3000 lifepoints before this update.
- On the same 17 June 2013 update, the slayer experience rewarded increased from 73 to 360.5, to compensate for their increased strength.
- Due to excessive botting, an update on 7 August 2012 removed several rune armour drops from the drop table of mature grotworms, replacing them with their adamant counterparts, making it less effective to earn money. The same update also removed royal bolts and super restore potions from their drop tables.