|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 582
- Represents 90% confidence range, based on a sample of 6,931 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 2,167 Adamant sq shield 1 Common 1,787 Rune dagger 1 Common 4,213 Rune helm 1 Common 10,755 Rune mace 1 Common 7,806 Rune longsword 1 Common 18,331 Royal cape 1 Rare 401
Item Quantity Rarity GE market price Grimy guam 1 Uncommon 399 Grimy marrentill 1 Uncommon 99 Grimy tarromin 1 Uncommon 31 Grimy harralander 1 Uncommon 84 Grimy ranarr 1 Rare 2,445 Grimy irit 1 Rare 1,594 Grimy avantoe 1 Rare 3,172 Grimy kwuarm 1 Rare 2,675 Grimy cadantine 1 Very rare 1,634 Grimy lantadyme 1 Very rare 6,877 Grimy dwarf weed 1 Very rare 7,353
Item Quantity Rarity GE market price Fellstalk seed  2 Common 986 Belladonna seed 1 Rare 82 Cactus seed 1 Rare 37 Poison ivy seed 1 Rare 9 Toadflax seed 1 Uncommon 964 Irit seed 1 Rare 178 Avantoe seed 1 Rare 2,493 Kwuarm seed 1 Rare 60 Snapdragon seed 1 Very rare 2,480 Cadantine seed 1 Very rare 692 Lantadyme seed 1 Very rare 27,201 Dwarf weed seed 1 Very rare 34,150 Torstol seed 1 Very rare 21,263
- ^ No anagogic ort is dropped along this drop.
Item Quantity Rarity GE market price Flax 50 (noted) Common 4,450 Runite ore 1 Common 11,082 Adamantite ore 3 (noted) Common 3,918 Royal dragonhide 1 Uncommon 5,422
Item Quantity Rarity GE market price Coins 1,000 – 5,000 Common Not sold Saradomin brew (2) 1 Common 589 Shark 2 Common 2,030 Blood rune 20 Common 9,800 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 1,282 Uncut emerald 1 Common 2,561 Uncut ruby 1 Common 3,027 Uncut diamond 1 Uncommon 5,572 Loop half of a key 1 Uncommon 34,719 Tooth half of a key 1 Uncommon 34,657 Uncut dragonstone 1 Rare 14,477 Dragonstone 1 Rare 9,933 Dragon dagger 1 Uncommon 16,483 Rune battleaxe 1 Rare 24,195 Rune javelin 5 Rare 910 Adamant javelin 20 Very rare 1,220 Rune 2h sword 1 Very rare 37,468 Rune spear 1 Very rare 11,446 Dragon spear 1 Very rare 36,368 Battlestaff 200 (noted) Rare 1,554,000 Rune sq shield 1 Very rare 22,166 Rune kiteshield 1 Very rare 31,864 Shield left half 1 Very rare 63,182 Dragon helm 1 Very rare 58,770 Adamant bolts 200 Uncommon 13,000 Onyx bolts 150 Rare 1,273,200 Rune arrow 150 Rare 22,650 Vecna skull 1 Very rare 96,512 Water talisman 1 Uncommon 10,552 Earth talisman 25–35 (noted) Uncommon 62,475–87,465 Fire talisman 25–35 (noted) Uncommon 62,850–87,990 Chaos talisman 1 Uncommon 713 Nature talisman 1 Uncommon 463 Pure essence 1,000–1,500 (noted) Uncommon 17,000–25,500 Nature rune 60–80 Rare 18,420–24,560 Soul rune 20 Rare 4,200 Law rune 45 Rare 19,080 Death rune 50 Rare 15,050 Blood rune 50 Rare 24,500 Raw swordfish 125–250 (noted) Uncommon 59,625–119,250 Raw shark 250 (noted) Uncommon 281,000 Big bones 150–180 (noted) Uncommon 87,300–104,760 Coal 550–700 (noted) Uncommon 133,650–170,100 Adamantite ore 150–250 (noted) Uncommon 195,900–326,500 Silver ore 100 (noted) Rare 9,400 Runite ore 100 (noted) Rare 1,108,200 Rune bar 1 Common 14,132 Rune bar 50 (noted) Very rare 706,600 Clean toadflax 35–45 (noted) Uncommon 119,385–153,495 Clean snapdragon 30–35 (noted) Uncommon 108,240–126,280 Clean torstol 16–34 (noted) Uncommon 91,616–194,684 Snapdragon seed 1 Common 2,480 Torstol seed 1 Uncommon 21,263 Watermelon seed 3 Uncommon 8,547 Magic seed 3–7 Rare 522,369–1,218,861 Palm tree seed 10 Rare 1,349,520 Yew logs 450–550 (noted) Rare 160,200–195,800 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.