No one reason will result in spells going wild like this and becoming living beings. Sometimes it is a botched casting, other times wild magic area or just the target making their save. All are at least average rodent level intelligence, unless otherwise noted. Hostility level varies greatly but only a very few will be helpful(but not unknown). Most also fly unless otherwise noted.
1 Charm Person
Manifests as baseball sized glowing green globe.Gains control of nearest sapient life form(No Save) Victim immediately melees nearest living being as it's eyes glow green.Physical damage is split 50/50 between Spell and target.Will move to other targets if first one is rendered unconscious.
2 Inflict Minor Wounds
One of the non-fliers, moves about 40 ft a min. slithering on the ground as a black irregulr square. It will slither up anyliving thing that it can catch.Will do damage as long sword(no save) as previous wounds of the target open up. Only killed by cure spells. Low Hit points.
3 Burning Hands
Spell is a 15' flat semi circle, 1 inch thick, living flame. Flaps like a bird to fly quickly. Attacks and damaged like normal low level creature with a 2 handed sword., takes double damage from water and cold spells, Low HP, moderate difficulty to hit them from high agility
4 Cure Light Wounds
When not attached to a weapon, looks like standing 2 D white shadow of a humanoid. It ataches itself to the most magical weapon in it's general vicinity and becomes invisible The weapon now in addition to inflicting it's normal damage now also casts a minor cure spell on whatever it hits. Only removed by curse effecting spells.
This spectacular looking spell bursts into harmless mini fireworks about the size of a beach ball. Will follow you around like a puppy giving a beautiful and attention getting display .Dispelled by one full minute of applause from at least three individuals.
Looks like semi transparent tower shield. Interposes itself between combatants providing minor shield bonus to random individuals. Destroyed by moderate damage, Takes 1/2 damage from non-magical sources.
7 Warp Wood
Invisible force that creates impotence. easily cured with Dispel Magic or any curse effecting spell , but then moves on to nearest male after it reforms in 24 hours. Silly urban quest to permanently rid Royal Castle of it.
Silver Glowing fist of human intellect, that hates spellcasters. Will rap on spellcaster while they are casting, causing a moderate chance of spell failure. Only damaged by non-magic weapons.
Invisible force that causes wild fluctuations to the infected's luck. 50/50 chance every die roll will go up or down by d4(will vary with system used). Only way to rid yourself of it is to make 2 critical successes and or failure in a row. Force will disperse for 24 hours then will reform where it was dispelled, waiting for next target.
This 2' square, 3 inch thick, pale blue Spell will go under your feet and either smash you into the cieling or drop you from 30'.Moderate HP and difficulty to hit.
One of the few beneficial Living Spells, this looks likes a giant transparent red bird claw. The force envelopes you and is visible while attached.It modifies all your die rolls by +1 untill you go to sleep or are knocked unconscious.
12 Bark Skin
This man sized green cloak looking Spell will envelope you and cause your clothing and armor to be ill-fitting and less effective as a green glow peaks out from them. It is dispelled when you take 1/2 your HP in damage in under an hour.
13 Magic Missile
This Spell lurks in dark, indoor spaces. It is of ape intellect and will iniate a hide and seek form of attack, striking quickly from shadow and speeding off. Moderate damage is caused by this. Damaged only by physical weapons, it is EXTREMLY difficult to hit but is of low hit points.
14 Gust of Wind
This unseen force is roughly horse sized and greatly inhibits movement in its area. Low Hp but both incorporeal and invisible.
For decade's sages and mystic have been baffled by this one. A harmless cantrip that far too frequently manifests as a nuisence. Starting as a lemon brown gassy cloud that attacks it's targets mouth with moderate skill in an attempt to get inside. it has Low Hit Points and is difficult to hit.due to size. If it gets in the target has uncontrolled flatulence for 2-5 days.
This Very swift 30' diameter gassy globe is volume filling. It causes x3 movement and physical attacks to all within it., speeding up individuals till spellcasting is nearly impossible(High chance of spell failure) High HP, Only effected by magic and magic weapons. , Non-corporal. Attacks must be directed at it to hurt it. Area effect spells do double damage.
17 Lightning Bolt
Looks like it sounds. High speed, HP , damage and moderate difficulty to hit it.If grabbled by metal armored foe , can be grouded out.
Causes targets ears to glow green and hear loud nonsensical whispers, greatly impacting hearing. Only damaged by dispels.
as Fart but attacks eyes, causing them to glow golden brightly . This causes a surprisingly mild loss of vision and enables target to make a gaze attack that inflicts moderate damage to undead. Dispelled by curse effecting spells or being knocked unconscious.
20 Mage Armor
As your systems living shadow but immune to light spells, double damage from cutting weapons.
21 Remove Curse
as Fart but man sized and envelopes targets whole body, causing it to glow purple. Subject is 100% magic resistant and magic items do not function. No remedy, Spell dies after 2d12 hours.
22 Raise Dead
Invisible Spell that reanimates all the killed opponents of the target for 1d6 hours, then dies. Subject mildly regenerates while infected.
Attacks as Fart but appears as blue egg. If it successfully enter targets body, thier vision causes non magical writing within 20 feet to disappear. Magic writing needs to make easy save(Once per approx. page of material) lasts for 2d6 days or until Spell fails save vrs. a dispel.
24 Dispel Magic
This Mage intellect spell follows casters and attempts to dispel all their castings, Invisible and non-corporeal, Immune to magic but not magic weapons Moderate HP.
Spell causes weapons to become invisible wreaking havoc with your ability to use them. Killed by remove Curse, dies after 2d6 hours.
26 Color Spray
Attacks as Fart ,looks like rainbow colored dagger. Causes Target to change into solid random colors every d6 hours. Permanent.
Attacks as Fart,looks like yellow sheet of paper. Causes target to fail next d6 saves. Killed only by wish.
28 Mirror Image
attacks and looks like Fart, cause target to be the recipient of Mirror Image spell. Dies as spell expires
Literally living darkness(as spell) Causes minor damge to all inside, every combat round, moderate HP incorporeal,dispelled by anything that would effect base spell in system
Randomly appears as another Spell on this list ,Must be destroyed 3d6 times.