A Plagazon (also known as a Poisonzon) is an Amazon build that specializes in the Plague Javelin and Poison Javelin skills. It is a less common alternative to the Thunderfury build. It relies less on synergies than the Thunderfury, which leaves you with more wiggle room for passive skills. Not all players take poison damage seriously, but its potential to do massive damage can't be ignored.
Stat Distribution Edit
Strength: Enough to use your gear. Don't put in more than you need.
Dexterity: Enough that you have maximum block.
Vitality: Anything else.
Energy: Should be left alone. Equipment and potions will cover this.
Maxed Skills: Edit
20 Plague Javelin - This is your bread and butter. Works best for crowd control.
20 Poison Javelin - Provides synergy for Plague Javelin and is useful when not fighting groups.
Other Important Skills: Edit
1+ Valkyrie - Your handy-dandy meat shield. She helps keep enemies away from you.
1+ Critical Strike - Gives a chance of doubling your damage. This doesn't work with poison, so it's not as important as the other skills.
1+ Penetrate - Increases your Attack Rating, which makes you hit more often.
5+ Pierce - Creates total havoc in crowds, doing even more damage.
1+ Lightning Fury - Optional, and makes this build more of a hybrid.
All passive skills should be taken at least once. After that, you can decide where to distribute your points. Lightning Fury is useful for PvP and for Poison Immune monsters.
Plagazons have the advantage of running into fewer monsters immune to their damage than say, the Sorceress. Some monsters, usually Undead and constructs are immune to poison. In Nightmare and Hell this number increases significantly, and there are even some immune to both poison and lightning damage. On Hell difficulty, it may be a good idea to get a Rogue Archer with Fire Arrow or Cold Arrow in case you run into Poison Immune Monsters (or poison and lightning immune if you're a hybrid).