This is my idea for a fairly viable Rammus troll build. Basically the idea is that by building Spell Vamp and AP after armor, enemy attacks will actually heal you Please note, this could be entirely ineffective as I haven't managed to complete this build in game, but the theory is solid.

Runes:
Magic Pen Reds
Armor/lvl Yellows
AP/lvl Blues
Flat HP Quints

Masteries:
0/22/8

Build:
Merc Treads
Thornmail
Sunfire Cape
Guardian Angel
Hextech Gunblade
WIll of the Ancients

Theory:
With this build, you have (with defensive ball curl) ~480 armor, and each enemy attack deals 107(+30% of enemy damage) to the attacker. With 50% spell vamp, you are of course being healed for around 60 each enemy attack. Additionally, your Sunfire Cape is dealing 35 DPS, so that's (after MR) healing you for 10-15 hp per second per enemy target nearby. The fun thing is, with 480 armor, the enemy champ has to have quite high DMG to avoid healing you with each hit Plus, your Attack Damage is in the realm of 300 or so due to all the armor you have. Add the 250 DPS AOE your Tremors has from the AP items (healing for half of that the enitre time) you would be quite difficult to kill. This build still offers about 100 MR, so your effective magic health is still about 5000. Also, if you get focused down by AP, your GA will leave them raging.

This is probably a terrible idea, but seems pretty fun A hard AD counter that can deal over 2000 damage to structures in 8 seconds seems like a solid addition to any team.

Post your thoughts

seems legit xD

Roll with it

unfortunately, spell vamp only works on damage from skills, so the thornmail return damage and sunfire passive won't heal you.

HOWEVER, the DBC return damage and tremors and powerball will still heal you for awesomesauce

seems like rammus isn't an AP carry. me azn no likey this.

@FailzorBringer, Thanks for the feedback, was unaware that thornmail and sunfire didn't return spell vamp Oh well, that's just a small amount as it is. Did a little more research, and at the end of this build the enemy attacker will need more than 300 attack damage to not be healing you (that's without thornmail)

The biggest problem with this build is that its pretty expensive, but tenable about 50 minutes in.

5PD , GA = bg

...
Spellvamp only gets 1/3 heal on AOE...