The arrival of the Necromancer was foretold at last year's BlizzCon, when Blizzard announced that the creepy exploder of corpses from Diablo 2 was being "reimagined" for Diablo 3. The studio put some of his abilities on display last month, and now that the beta is live, you can—with a little bit of luck—check him out for yourself.
"As a master of the dark arts, you wield the powers of life and death necessary to restore the Balance!" the beta announcement states. "Necromancers are powerful spell casters who lay waste to their enemies using curses and reanimation—along with an obedient cadre of pets. This new class employs a controlled gameplay style using the raw materials of life: blood and bone."
The Necromancer beta is closed, so you'll need to opt in to Diablo beta testing via your Battle.net profile settings page, and then wait (and hope) for the "you're in" email to arrive. Blizzard will also be inviting "key members of the community on a case-by-case basis" to take part, so if you fit the bill you might get lucky that way, too. An ending date for the beta hasn't been determined yet, and Blizzard said that more testers will be invited to take part if, and as, necessary.
The beta test includes not just the Necromancer but all other 2.6.0 patch content, including new Challenge Rifts, two new zones for Adventure Mode, improvements to Set Dungeons, and four new Waypoints in Act 4, each with new bounties to complete. A more detailed breakdown of the Necromancer's powers, with the caveat that it's all still under development so "both numbers and functionality may still be subject to substantial change," is up at battle.net.