Ick Swamp is a Hard difficulty dungeon in the Beta, filled with plants and other dangerous monsters. It is unlocked by completing the southern swamp.
The dungeon contains all types of plants, excluding barbing bushes, gorgons, vampires, sorcerers, and naga. The boss is Ssseth, the naga, with 318 hit points, 37 damage, 60% physical and magical resistance, and weakening blow. All sorcerers killed drop wisp gems. Wisp gems are small slot items that give +5% attack bonus.
You want to level up using gorgons, vampires, and sorcerers because they all have relatively low hp. Nagas are to be avoided unless they can be killed without incurring any weakening. The plants are very dangerous and hinder your movement, but avoid killing the poison and mana burn plants unless you're about to level up. If possible, before you level up, clear out all the poison and mana burn plants. Corrosion can not be removed easily, so it is recommended you avoid getting any. Before you begin the boss fight, make sure you have killed all sorcerers and pick up all wisp gems.
The boss, Ssseth, has very high resistances and weakens you, so a low damage character is not recommended. If you decide to go the spell casting route, it is also highly recommended you bring the piercing wand to counteract his high resistances. Ssseth's weakness is his damage, even a level 6 rogue can take a hit without dying, so this makes HALPMEH an incredibly valuable glyph. Berserker and rogue are very good class choices. If you choose a rogue, you must either find HALPMEH, CYDSTEPP, or an altar to Taurog, because health potions will not last you long enough. If you find a CYDSTEPP glyph, start killing sorcerers, gorgons, and vampires 2-3 levels above you. If you find HALPMEH, it will be monsters 1-2 levels above you. If you find Taurog, only pickup the sword, boots, and possibly shield, as you need the rest of the space for wisp gems. If you go the berserker route it's Taurog time! Grab the sword, boots, and helmet first converting all glyphs and killing high level sorcerers with your new 65% magic resistance. The boss should be easily outlast able with any of the 4 tactics.
Great items to bring are whupaz, burn and fortitude potions, as these will help with clearing out the plants and dealing with the boss. Anything that improves base damage is great, especially tri-swords. If you bring a tri-sword, play a halfling, as they get 30 base damage out of it. All the extra base damage will combo extremely well with the wisp gems you'll be picking up and you will end up with very high attack.
=Special Interactions with Plants
The harmful plants of the Ick! swamp can be exploited as a resource under limited conditions. A worshiper of Glowing Guardian equipped with HALPMEH can and should poison himself whenever he is at full mana and about to explore, and at any point in time during a battle where he intends to cast HALPMEH. Whenever practical, you should also try to get poisoned and manaburned just before leveling up. A character following this strategy will actually want to conserve the plants rather than just cut them down.
It may not look like it, but the harmful plants apply their effects by making a zero-damage attack. This attack can be dodged like any other attack. Rogues following Tikki Tooki can gain very large amounts of piety by harvesting the plants right before level up. Taking the Dodge boon makes this even better.
Killing a plant, even the harmless green ones, still counts as a kill and still discharges IAMAWAL. Be cautious that you don't waste your bonus experience on a 0 xp kill!
There are 2 quests in ick swamp, Ick! and Way of the Open Fist (part 2). For completion of Ick! you gain 250 gold. All you have to do is beat the dungeon. Way of the Open Fist (part 2) requires you to beat the dungeon as a monk without preparations. This requires quite a bit more luck than normal, as you must find an Altar to Taurog asap. Find Taurog and then convert all of the glyphs you've found so far for extra base damage and take the sword. Regen fight monsters (except naga) until you are level 8. Make sure you have extra tiles as you are going to need them. Start off with potions, then tiles until you can kill him in 3 shots (or 4 if you have 2 altars you can afford to desecrate), then use unstoppable furies for the kill. This will take many tires so try not to get frustrated.