Hacking the Classics: Rust monsters on Planet Psychon

Celebrating Psychon settlement post racing to no1 in my blogroll for some reason

Usually named according to colour plus beast or monster - or by the power

Random Psychonian rust monster skin colour
1 in 10 is a crossbreed with powers and colour of two types

1 Crimson (red, brick, maroon) Combustion touch, burn 1d4 for 2d4 rounds Pyro monster
2 Magenta (rose, pink) Drain blood or life by just a touch 2d6 each touch Hemo monster
3 Cyan (sky, light blue) Drain magic objects or magicians minds 1d3 lv/+  per touch Arcano monster
4 Turquoise (sea, turquoise, aquamarine) Ages 1d10 years per touch Chrono monster
5 Yellow (gold) Crave gold, silver, platinum and copper Treasure monster
6 Tangerine (orange, bronze) Standard craves iron and steel Rust monster
7 Emerald (olive, forest) Petrifies target then eats slowly by licking Geo monster
8 Green (lime, light green) Green slime infection Bio monster
9 Violet (Indigo, purple, lavender) Turns food and water to dust Polyphage monster
10 Lapis (dark blue, midnight, navy) Disintegrates wood and leather Void monster
11 Ivory (bone, pearl, shell, silver) 2d6 Freeze touch and slow rounds Stasis monster
12 Jet (grey, slate, steel) Level draining wight like effect Necro monster

Other special Psychonian rust monster abilities
1-5 no special powers
6-7 one special power
8-9 two special powers
10 have 1d3+1 special powers

1 Spider Climb (drop from ceiling)
2 Glider Wings (glide from trees or cliffs silently)
3 Extendable tentacles, twice range
4 Regenerating tentacles as long as eaten some special food
5 Slam attack, save with STR or knocked prone from charging beast
6 Shoots magic missile from tail every round
7 Tail blade 1d10 damage 360degree arc
8 Ram attack 1d6 headbutt and 2d6 if charge
9 telekinetic limited to food type, magnetic power for rust monster, 100lb per tentacle
10 Throw baby monsters with tail 1HD each 2d4 shots 50" range
11 Shocking grasp, 1d4 every time you hit it with a melee weapon
12 Special colour based Elemental power as below table

Crimson (red, brick, maroon) Fire and heat resistant, live in volcanoes
Magenta (rose, pink)  Everyone in 30 feet loses a d6 HP per round if enraged
Cyan (sky, light blue)  Can cast spells it steals once like a scroll
Turquoise (sea, turquoise, aquamarine) Can dimension door at will
Yellow (gold)  Grown gems in hide, sings sweetly, desired pet of kings
Tangerine (orange, bronze)  Cone effect rust power 60' 30 degree arc, 3 times per day
Emerald (olive, forest)  Poison blood spray on death all in 20 ft hit by poison
Green (lime, light green)  Acid blood, damages incoming weapon, 1d4 everyone in 5ft
Violet (Indigo, purple, lavender)  Each tentacle destroys a d6 of undead HD
Lapis (dark blue, midnight, navy) Can fly into space with a passenger with beetle wings
Ivory (bone, pearl, shell, silver) Healing 1hp per round of touch if happy eats scar tissue
Jet (grey, slate, steel) Eats your shadow, interferes in souls passage to next life

Rumoured Otherworldly Powers d12
Double size ones from other planes have been noted and may possibly have the following powers

1 Intelligent sentient being
2 Polychromatic, can change colour and powers at will
3 Phaze powers (pass through solids, surprise attacks) if phased +4AC need +2 magic to hit
4 Plane Shift (use to escape, returns to home plane for 1d12 months if killed)
5 Pincer Arms like scorpion or tentacles like a squid (meanest) 1d8 or grab attack each
6 Invisibility (stalk party silently)
7 ESP (learn preys plans and food keeping secrets)
8 Illusions (trick victims out of food)
9 Regeneration 1pt per round, must destroy till -10 to kill
10 Tail sting with deadly poison like a scorpion +1d12 (stacks with tail attack if any)
11 Summon 1d4 more monsters 30% chance once per day
12 Roll 1d10 twice

On planet Psychon they are sometimes used in swarms for terraforming hexes by gods. A spiteful god may use these monsters to punish a civilization - steam-punks would melt before a rust monster plague. Breeding programs with planar beings and other monsters is a practiced art among some biomancers. Poor monsters with no metal breed them against their kin that do use metal. Some breeders keep packs of several strains and teach them to attack together. They are resistant to their own breeds harmful powers. Cross breeds are viable. Different colour eggs sometimes appear in pure strain clutch. Some otherwordly types can change colour and species every round and they may lay eggs of any colour and act as a queen..

If you meet a band of naked dirty knights, rust monster encounter up ahead