Lobster

A lobster is a type of shellfish that players can use as food. Players can catch a raw lobster with a Fishing level of 40 or higher, granting 90 Fishing experience. Lobsters can be caught at any Cage/Harpoon fishing spot with a lobster pot. Raw lobsters can be cooked with a Cooking level of 40 or higher, granting 120 experience on a range and 132 on a bonfire. A full inventory of 28 lobsters grants 3,696 experience if all cooked on a bonfire. Players may accidentally burn lobsters while cooking until they reach a Cooking level of 74(or 68 while wearing Cooking gauntlets).

Other
Noted lobsters can sometimes be found inside barrels.

Free-to-play popularity
They are the most popular food for player-killing, due to their low price and the fact that they can easily be collected in bulk. Wealthier players will use lobsters while training on monsters as well.

It is also common for players to fish and cook lobsters on Karamja, use them to train on lesser demons in the dungeon and then repeat the cycle. Bring a tinderbox and hatchet of any kind, cut a dead tree near the volcano entrance to make a fire. Less wealthy players will find trout (200-300 Life Points) and salmon (200-500 Life Points) more cost-effective ways of training combat.

In free-to-play worlds, before the Grand Exchange was released, lobsters were one of the most profitable commodities to players fishing for them as well as merchants in Edgeville and many other banks. This is partly because Edgeville is the nearest town in the wilderness that has a bank where players of clan wars, player killers, and wilderness duelers prepare and these players are in need of food during battles. Traded in bulk, cooked lobsters could sell from 200 to 250 coins each and rarely can even sell for 300 coins each.

When the Grand Exchange was set up in Varrock and the 10 December 2007 updates took effect (which put up the 5k trade limit, removed player-killing in the Wilderness), prices of cooked lobsters dropped from 250 to 200 coins to as low as 150 to 200 (due to the ease of trading cooked lobsters), but prices of raw lobsters sky-rocketed from as low as 100 coins each to as high as 339 each. The increase in the prices of raw lobsters was due to the fact that loss of macroers, which provided most of the supply of lobsters in the economy, were also lost. However, when player-killing worlds were put up, which also increase the demand for food, prices of cooked and raw lobsters rebounded to beyond 300 coins where it stood for a few weeks before slowly declining to around 250 coins. With Stiles added to the game, players were able to procure much greater number of lobsters in Karamja, causing oversupply of lobsters and consequently cause the price of cooked lobsters to dip to its present value.

Pay-to-play popularity
While lobsters are often used for training on pay-to-play servers and low level players, it is not recommended that they are used for player killing. Instead, rocktails, sharks or at least monkfish are recommended so that the player is not easily killed. An alternative for members with low level Fishing is to use the thieving skill to steal them in Rellekka or Miscellania at level 42 thieving, though in Rellekka there is no bank nearby to store them—unless the player is wearing Fremennik Sea Boots 1, 2, or 3 (obtained by completing the Fremennik Province Tasks) in which case you can talk to Peer the Seer to access a bank deposit box. If you wish to cook the lobsters before banking them, Yrsa has an everlasting fire in her hut, quite close to the marketplace.

However, most members use lobsters for questing and training combat on low to medium-levelled Non-player characters, and/or when they need quick cheap food.

Macros
Lobsters are a popular item for macroers to produce, especially in free-to-play worlds at Musa Point and member worlds at Catherby, because of the high demand of both raw and cooked lobsters, and they would sell for quite a good profit.

This was all changed by the "Trade and Drop Changes" game update on 10 December 2007, which attempted to block virtually all forms of real world trading from the game. As a result, lobster fishing macros became rare.

Due to the disappearance of macros, the price of raw lobsters began to sky-rocket, rising to over 400 coins. However, when Stiles was created on 21 April 2010, macros became far more common and lobster prices decreased.

When free trade was reintroduced on 1 February 2011 macroers have begun sprouting on virtually every world and raw lobster prices have decreased significantly.

Even after the ClusterFlutterer update, which banned a majority of bots, lobster prices continue to plunge.

Trivia

 * Back in RuneScape Classic, the colour of the lobster was actually the other way around. Raw lobsters were a bright red colour when caught, and turned a deep brown when cooked. It was not until the implementation of the RuneScape 2 upgrade that it was changed to the way it is now.
 * There is a glitch while fishing, if you have started barbarian training, start to harpoon fish without a harpoon, while wielding a magnifying glass with a lobster pot in your inventory, then start to cage lobsters, you can move your hand rapidly like barbarian harpooning but the text "You attempt to catch a lobster" will appear and you can still catch lobsters until you stop. This glitch has not yet been fixed by Jagex. There are no benefits from performing this glitch.
 * On the coast line of Daemonheim and in the far east of the lower levelled wilderness, there are non-attackable cyan-coloured Lobster NPCs that can only be examined. They have levels: "Examine Lobster (Level 4)", which is probably a bug because they used to be attackable, and when they were attacked, they dropped raw lobster. The examine of these NPCs is: He looks really cold.
 * While fishing lobsters in Catherby, there is a slight graphic glitch where if the character is viewed from above, when the cage is plunged into the water, the avatar's head also appears to be underwater. This has also been known to work at Karamja, at the right angle.