Dolphin

Raw dolphin can be fished by members who have level 90 Fishing or higher. They require level 93 Cooking to cook and heal 250 life points each. Dolphins are fished with harpoons. Raw dolphins can only be fished in deep sea areas. Dolphins give 300 Fishing experience per catch and 350 Cooking experience when cooked.

Catching dolphins can take a really long time, so it is not advised to catch them if you are planning on leveling your fishing, but when caught they can be sold for a reasonable price.

At level 103 Cooking, players will stop burning dolphins if they wear  Cooking gauntlets. By cooking dolphins, players gain about ~441,000 xp/hour, assuming they have 103 cooking and wont be burning any dolphins.