Batman: Arkham Asylum

The Poison Ivy / Titan Plant boss battle is part of the main story, so it's unmissable.

Making sure you have fully upgraded your armour, and upgraded your batarang so it causes greater damage will make this battle slightly easier.

The battle is split in to two parts.

PART 1
The first part consists of 2 or 3 sets of 2 vines rising out of the ground, followed by Ivy firing spore balls at your position.

When Ivy's vines are attacking, watch for where the grass lines appear. Standing in the middle means you can dodge (douple tap A) to either side, and while the vines are up use your batarang (tap LT) to inflict a little damage. Try and make sure you are not near the grass, as sometimes you can get caught even if you think you are clear.

When Poison Ivy fires the spore balls, make sure you have the whole width of the ground to run along. Run as she fires the first (hold A), then as she fires the second use the batarang (tap LT) to hit her opened shell, followed by a dodge (double tap A) to make sure it misses and you avoid the third and fourth. Each time you hit her and the sequence ends, she will fire several spores which you should just focus on avoiding; and running back to the side to attack again. This approach meant I didn't lose any health to the spore balls; just to those damn vines!

PART 2
Once she has lost her health the first time, and you have planted the explosives; you will have to attack her again. The game will helpfully give you back some of your health.

At this point, goons will attack you at the same time as the vines.

Try to run around so that the vines attack the goons that follow you around, and leave you in an area free of vines and goons so that you can use your batarang on Ivy. It only takes a tiny bit of her health each time, but you should be aiming to reduce her health by half in this first attack.

If you find yourself in a grassy area, use the dodge (double tap A) to jump over the goons and to safety.

Should you find yourself safe from the vines but with a couple of goons, it is better to focus on killing them and saving your health than hitting Ivy. Also, if you are waiting for a vine attack take the opportunity to attack the goons.

Remember, if you're on your own, use the batarang on Ivy!

Using this approach should mean Ivy loses around half her health by the time all the goons are killed. The spore attack sequence that follows is exactly the same as previously; so exactly the same run, throw, dodge method can be used. If you can hit her every time, you should find that when the goons start to reappear, she only takes just a couple of hits to beat.

Congrats!

I recommend earning enough EXP to max out the health upgrades before confronting Poison Ivy. While you do more damage when the doors around her are open and the plant is attacking, your batarangs will still do damage with the doors closed, just not nearly as much. The plant won't fire spore balls at you while the henchmen are fighting you, so I found a good tactic is take out some of the goons and then avoid the last few and try and spam Ivy with as many batarangs as you can, while avoiding the vines that pop up underneath you. The vines will also incapacitate the goons if they get caught, creating moments where you're free to fire a bunch of batarangs before you need to move to avoid henchmen or new vines.

This achievement is awarded to you once you defeat Ivy's and her titan plant boss, rather then provide you with a wall of text to read through I've linked in a video which will walk you through what you have to do, I'm also going to give you a few tips.

• Spam your batarangs, it'll only damage her/it a small amount but it will really add up and is vital to do on hard mode, literally whenever you can safely throw a batarang up at her/it do so.
• Upgrade you armour, doing so will mean you that you can take a few more hits, you'll survive longer against what many describe the hardest boss in the game.
• Try and take out the goons as quick as you can, this one may seem obvious, but I mean you should try and take these goons out as they spawn, throw them off ledges, stun them so they get killed off by the attacking vines.

Taking those tips into consideration and using the video below you shouldn't have too much trouble with this boss and getting the achievement!

* ^{Credit to killergp123 for the video}

This fight can be quite difficult if you don't have all the armor upgrades so I suggest solving some riddles until you can get at least 3/4 of them. The First half of the battle shouldn't be too difficult as long as you just keep slinging quick tap batarangs at her, all the while avoiding the spores that she 'shoots' at you from her tendrils or tentacles or whatever you'd like to call them. The Guards that she summons are fairly easy to beat, but to defeat them even quicker either target them with a batarang while they are being pulled up by Poison Ivy or Melee them off the edge as soon as they are dropped onto the little island where you are. The Second part of the battle can be a bit tricky, as the thorns she summons can easily trap you if you spend too much time on the Guards - BUT they can get trapped in the thorns as well so use that to your advantage. When Ivy has gone up to the higher elevation and exposes herself just throw a quick batarang and it should always go straight to her. I usually do this after the first spore ball she shoots when she is exposed and I Dodge Roll right after I quick batarang her to avoid the next barrage of spores.

NOTE: Credit goes to the original uploader on YouTube for this video.

I found a great video walkthrough for the Ivy boss battle. Credit goes to BatmanArkhamVideos on YouTube. I did not make and upload this video.