Zulrah

Zulrah is a safe-zone and you will not lose items upon death.

Preparation

If magic is your better combat style then this will be sufficient, however, range gives faster kills.
So gear up with your best set.
Bring 1-2 Rings of Recoil (for the snakelings), Anti Venom potions, Overloads/ Range or magic potions, Super Restore/ Prayer Potions, and your best food.
If you kill Zulrah fast enough (before its range phase) you won't need to worry about the Anti Venoms.

The Fight

See the image below for Zulrah's attack sequence, where to stand, and what to pray.
Start out by standing on the white tile for the first 6 phases and pray accordingly. Here you will take no damage (excluding from snakelings).
In the 7th phase you will take Venom damage so use your Anti-venom Potion.
When the 8th phase begins start moving (in between your attacks) to prepare for phase 9 to avoid venom cloud damage.
After phase 10 Zulrah will restart this same pattern, however, there is a chance of a random phase after phase 10. So pray accordingly.
Remember to swap to your Ring of Wealth or Ring of Wytheria just before Zulrah dies for the D/R boost.

Rewards

Tanzanite fang
Magic fang
Serpentine visage
Uncut onyx
Tanzanite mutagen
Magma mutagen
Jar of swamp
Pet snakeling