They are commonly killed for the frequent drop rate of tortoise shells, used for creating a war tortoise pouch. They are also killed for their frequent drop of rune warhammers and pickaxes.
Their horrific appearance is a result of tampering with the Anima Mundi during experiments conducted by Glouphrie in Arposandra. The experiments have caused the tortoises to grow an additional pair of legs, as well as a group of purple tentacles protruding from their shell.
Warped tortoises are completely immune to incoming attacks unless the player has a crystal chime in their inventory. They mainly attack with magic, which can deal moderate damage, and quite accurately. They have considerable defence against melee and magic attacks, but are less well-defended against ranged, particularly crossbow bolts. The best weapons for killing them are dual Ascension crossbows, Chaotic crossbows, or even a Royal crossbow or the Hand cannon, although a Zaryte bow would also be effective.
There are relatively few areas where these foes may be killed without any interference from nearby level 82 warped terrorbirds, which are aggressive and attack with ranged and melee. One is at the entrance, where there are two quick tortoise spawns. A second is at the end of dungeon where there is a room with two warped tortoises alone which is not generally used by bots. This could prove useful for those on a Slayer task, particularly if they have 96 Summoning for a Pack yak. Some players may however find it unappealing to run through the length of the entire dungeon, tanking ranged attacks inflicted by the huge numbers of Warped Terrorbirds along the way.
Competition: Has been fierce at times, with bots sometimes infesting several of the worlds, reducing the chances of tagging a tortoise unless the player's reactions are very quick. Due to the small number of good locations, and the popularity due to slayer assignments and desire for the drops, players will often compete and attempt to force the other one to hop into another world. An easy way to deal with bots is to place your clan vexilium in front of the ladder to the entrance. Sometimes bots will also enter the next room (the one with terrorbirds) if both doors are open.
Multi-hitting: A Dwarf multicannon can be used in the dungeon. However, this will attack immediately on target, and the chimes must be used manually on them. This however, while expensive to do, maintains your hold on the tortoises the player is currently attacking. This will also affect Ancient Magicks Burst and Barrage spells.
Healing: Warped tortoises can drop various amounts of items. They drop Tangled toad legs, which heal for a small amount, and can come in groups of one to three. This makes players who come to kill them bring little or no food, however the drop rate for this food is not common, so players may need to bring food if they have low defence or armour without good resistance to magic.
Drops: Pick up stackables such as Swamp tar, Mithril ore, Law runes, and Coal. They also drop decent alching equipment, such as Mithril platebodies, warhammers, and Rune warhammers and pickaxes. Pick up any unique drops, such as Tortoise shells, Perfect shells, Long bones and Curved bones.
Prayer Flashing: Prayer flashing may be used to negate some damage. This is however no longer recommended as protection prayers now only block 50% of damage as of the Evolution of Combat update. This may take some practice to do, and doing this will force the player to attack one at a time to minimise damage.
At one time it was possible to heal using Guthan's set even when the tortoises were not made vulnerable by the crystal chimes. This was because at one point Guthan's set counted potential damage inflicted on foes even when actual damage was not possible due to prayer or other invulnerability. An update on 9 June2009 fixed this bug.
Warped tortoises are the highest levelled monsters to drop cabbages.
If you have a slayer Daily Challenge and you attack a tortoise without a chime, you won't be able to do any damage. But if someone else subsequently kills the tortoise, it will still count towards your Daily Challenge.
There seems to be a glitch where warped tortoises are immune to stuns; if stunned with Impact they will be unaffected, while if Asphyxiate is used the first hit will not stun while the remaining hits will.