General Method Description

Cave horrors are a great money monster. In addition to the chance at a black mask for Slayer (worth over 500k), they consistently drop large quantities of nature runes, noted teak logs, high-level herb seeds, some herbs and other goodies. There's a fair bit of randomness in the drops you get from these monsters. The black mask is rare -- I've sometimes gone many hours without getting one -- but I also once got 4 on a single Slayer assignment. I don't use a ring of wealth here, as I've never been able to determine for sure if it helps, but some people think it does.

The value of other drops is also quite random, especially herb seeds, which can range in value from under 1k to over 50k for snapdragon seeds. They also provide big bones on each drop, which you can carry home to increase your profits.

At level 96 Summoning, you can use the pack yak's large inventory in one of two ways. First, you could fill it with extra food so you stay longer fighting -- an hour long trip instead of 30-minute trips would easily be possible. But for the most moneymaking potential, I prefer instead to use its many slots to carry home dozens of extra big bones, herbs, and so forth, which adds to the profitability of this version of the combat method.

These monsters are fairly spread out in a large cave, so I recommend a full world for faster respawns.