Anti magic vision is a bitch ain’t it

Don’t worry, Twilight! You have the perfect eye-jabber built into your forehead.

@Alex12  
so therefore twi is a complete bloody fool for getting up close and personal with one of the ever-frees top predetors

@Deserter  
Most teleportation spells are standard actions, which means they wouldn’t have an action left to attack until the beholder got in another volley.  
Much better to teleport away and then come back with a big beefy ubercharger (a Raptoran or someone else with nonmagic flight would be ideal, if you can manage it) or some other nonmagical beatstick. Barring that, you can scry’n’die it with the right spells. But if the party arcanist is getting up close and personal with a beholder, something has gone horribly wrong.

@coating human  
Can’t mages teleport stuff?

@Deserter  
I don’t see a war-hammer on her person

@Alex12  
Or she can just… smack it with a warhammer, or something.

@coating human  
Maybe, maybe not.  
The beholder’s own eye rays are just as neutralized by the antimagic cone as Twilight’s magic, and it can only open or close the eye once a round. So if it wants to zap her, it has to turn the antimagic off. And if she makes her saving throws against the eye rays, she’ll be able to get a spell off, ideally a teleport spell to GTFO. Or she could ready an action to cast a teleport spell as soon as the eye closes, that’d work too.  
So not necessarily fucked, but it’d be tricky. Beholders are CR 13 (that is, they’re considered a good match for a quartet of 13th-level D&D adventurers) and at that level, most spellcasters have access to 7th-level spells. At that level, a Wizard can cast Limited Wish, Plane Shift, and Greater Teleport, among many many other things.

@Alex12  
so twilight is pretty much fucked.

@coating human  
The central eye is an always-on antimagic cone generator. The beholder can “turn off” the effect by closing that eye. The other ten eyes have no specific function, but instead a whole host of functions. For a standard Beholder, these functions include Disintegrate, Charm Person, Charm Monster, Fear, Finger of Death, Flesh to Stone, Inflict Moderate Wounds, Sleep, Slow, and Telekinesis (all of which are similar or identical to the D&D spells of the same names as cast by a 13th level spellcaster)

@Background Pony #1CB3  
and that eye does what exactly?

Wrong eye glowing, it’s the center one that tuns off magic,

@Deserter  
“Over the centuries, mankind has tried many ways of combating the forces of evil… prayer, fasting, good works and so on. Up until Doom, no one seemed to have thought about the double-barrel shotgun. Eat leaden death, demon…” - Sir Terry Pratchett

Here, use this.  
 
The DooM Cacodemon sprite was based based on the Beholder’s and the Astral Dreadnought’s appearance, for those who don’t get it.

@Alex12
 
That’s only good for a party wizard, not the lone murder-hobo.

Because you rolled a wrong number.

@Zincy  
Or has friends who are good at hitting things with other things.

That’s why every good Wizard carries a blade or staff, for those pesky magic immune enemies.

Twilight, that’s a Beholder. Beholders generate antimagic cones from their central eyes. Start running.