A spider on stick can be made on Karamja during the Tai Bwo Wannai Cleanup minigame. Kill a jungle spider to get spider carcass, then use a machete to cut a thatching spar from the undergrowth around Tai Bwo Wannai, use the thatching spar with a machete to make skewer sticks, then use a skewer stick with the spider carcass. Alternatively, an arrow shaft can be used instead, resulting in a spider on shaft. The raw version cannot be purchased on the Grand Exchange; only the cooked one is available.
When the spider is on the stick, it can be cooked, granting 80 Cooking experience. A Cooking level of 16 is needed. When eaten, it heals a random amount of health between 7 and 10, and the stick is returned.
A spider on stick is needed to be cooked during a medium task in Karamja achievement diary.