Making a prismatic, uhm... bee holder.

[the David]

I'm working on a monster for a one shot, and its main power should be that it can attack with a Prismatic Spray-like attack on each round. It doesn't have to be a true Prismatic Spray though.

I've come up with fun alternatives like:
- rolling 2d4 instead of a d8 so you get that sweet bell curve that decreases the odds of petrifying/plane shifting all the PCs on the first round. This also eliminates the chance that you have a PC gets targeted twice.
- Rolling 10d8 damage instead of doing 20, 40 or 80 damage depending on the color.
- 30 ft. emanation rather than 60 ft. cone, or the choice between either.
- Attacking all the PCs once per round, rather than limiting the attacks by dividing them among 90° angles.

I was wondering what kind of monster I could use as a sort of template. So far I've got:
- Prismatic Orrery. Good, but can only do the prismatic thing once every d4 turns.
- A monster like the Medusa. Something that uses the same effect each round.
- 4 monsters disguised as 1. 4 times the hit points and attacks, but attacks and defends as monster that has a CR 4 levels lower.
- Adapting the 3.5 version and hoping against all hope that that somehow balances it.

Can anyone help me figure out if there are any other options?

[Bjørn Røyrvik]

You could make an actual prismatic beholder.
Each eye stalk has a different color and they function as normal beholder eye beams so you can't target more than one PC with any given effect. You can either keep the antimagic eye or have the central eye cast an actual Prismatic Spray with a breath weapon-like cooldown. Alternatively you can use 5e's version if you want more consistent damage and less SoS.

There are also my upgraded Rainbow Knights, originally from M3 Twilight Calling

Rainbow Knights
medium construct

Init +6
Perception +10
AC 32 t 12 ff 30 (+2 Dx, +20 natural)
HD/HP: 21/ 300
DR 10/- Fire/Cold/Electricity resistance 15, Acid resistance 30
SR 26
F +24 R +8 W +8

Speed: 30
Space/reach: 5/5
Special attacks
melee sword +27/22/17/12 4d6+16
CMB +28
CMD 38
Special defense: construct traits, shatter, immune to [light], chromatic and color effects
Str 26 Dx 14 Cn - In 4 Ws 10 Ch 4

Shatter: when reduced to 0 hp the rainbow knight explodes in a shower of glass shards, dealing 10d10 points of slashing and piercing damage (whichever is most favorable) to everything in 20feet (Reflex half, DC 25)
Refraction: when subject to an effect with the [light] descriptor they refract the effect into a Color Spray effect with a DC equal to the original effect

I ended up making their swords function as Jaran's Prismatic Blade because they needed to be beefed up to challenge my PCs.

Jaran's Prismatic Blade
(Evocation)
Level: Sor/Wiz 9
Casting Time: 1 standard action
Components: V
Range: touch
Duration: 1 round/level
Area: 1 blade of prismatic energy
Saving throw: special
Spell resistance: yes

You create a blade-shaped field of prismatic energy which you may make melee attacks against normal AC with at your normal attack bonus. Creatures struck by the prismatic blade are treated as if they had walked into a Prismatic Wall/Sphere, suffering all effects. They are allowed saves against each effect as per the Prismatic Wall spell. Also like other prismatic spells, creatures with fewer than 8 HD that look directly at you are blinded 2d4 rounds. The same spells that are required to get rid of a prismatic wall/sphere are required to dismiss this spell, though they need not be cast in any specific order. A Rod of Cancellation will also instantly destroy the blade.
Like with prismatic wall/spwere, this spell functions in an Antimagic Field, so long as it was caste before entering the field.
Known to: Jaran the Exalted One
Setting: Greyhawk

[Tim Emrick]

Green Ronin's Advanced Bestiary has a couple of templates that may be of interest to you: the Eye Tyrant gives the creature a bloated central body, atrophied limbs, and eyestalks that produce spell-like effects; and the Prismatic Creature gains abilities based on its shifting rainbow colors.

Both templates scale with HD. For example, the eye king gains one eyestalk per HD, and the highest-level spell any eyestalk can use is based on HD. (I statted up a T-rex eye king once, and it was obscene!) You probably don't want to use both templates om the same creature, as each one can be complicated (and both grant numerous spell-like abilities), but you could easily borrow ideas from the prismatic template when choosing spell-likes for an eye king.

[Tacticslion]

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[Azothath]

hmm... this gives me an idea.. thanks