Since the Lemming was suicidal there should be a non-suicidal rodent-mage, and this is it.

A Familiar can be various things. At the moment, you are a mouse, and you're Adria's Familiar. You can change your physical state and become more powerful, but these stages are covered later on.

The townspeople, save Adria, don't like rodents (they never do... except for those blasted Lemmings). You're gonna have to make the other townspeople see your power. Starting off, you may not use any townspeson (except for Adria) until you've proven yourself worthy to the town.

Spells are restricted to lower stages, but as you progress more become available. Spells that exist only on scrolls and staves may always be used.

1) Mouse
You have some parlor tricks but nothing good enough to take on the denzins of Hell.
-Spells: Firebolt, Healing, Heal Other (if Multiplayer), Charged Bolt, Staff Recharge.
-Max slvl: 3 -Progression: You must have a minimum of slvl 1 in each of the above spells, have found a book dropped by a unique creature, and Butcher lies dead. You can stair trap Butcher, but you MUST kill him with spells. (Melee allowed if dual-class.)
-Special Progression: Finding Wisdom's Wrap evolves you into a Gerbil. Finding Thinking Cap evolves you into a Rat.

2) Gerbil
You're becoming slightly more powerful and you're attempting to upgrade each of your spells.
-Spells: As before plus Inferno, Lightning, Town Portal, Holy Bolt.
-Max slvl: 4 -Progression: You have a minimum of slvl 1 of Inferno, Town Portal, Lightning and Holy Bolt and King Leoric lies dead.
-Special Progression: Finding Thinking Cap evolves you into a Rat. Finding Wizardspike evolves you into a Wild Cavy.

3) Rat
-Spells: As before plus Fire Wall, Telekinesis, Flash, Stone Curse, Phasing.
-Max slvl: 5 -Progression: You have minimum of slvl 1 of Fire Wall, Telekinesis, Flash, and Stone Curse. Moonbender(dlvl 4), Foulwing(dlvl5), and Wrathhaven(dlvl5) must be slain (in no particular order). A level of evil, orange Familiars must lie dead. -Special Progression: Finding Wizardspike evolves you into a Wild Cavy.

4) Wild Cavy
-Spells: As before plus Mana Shield, Flame Wave, Fireball, Elemental, Chain Lightning.
-Max slvl: 6 -Progression: Lazarus, Red Vex, Black Jade, Bloodlust Witchfire the Unholy, Witchmoon, and Stareye the Witch lie dead (in no particular order). Mana Shield, Flame Wave, Chain Lightning, and Fireball learned.

5) Domestic Guinea Pig
-Spells: As before plus Blood Star, Teleport, Golem, Bone Spirit.
-Max slvl: 7 -Progression Reached When: The whole game cleared and Diablo lies dead in Hell Difficulty.

6) Grand Familiar Capybara
-Max slvl: 15
Cool! You made it to the highest stage!

7) Special Stage: Weasel:
Weaselness is something that is quite revered in the realm of Familiars. Everyone seeks to become a Weasely Familiar. Few, however, reach the stage successfully. The minimum clvl to begin becoming a Weasely Familiar is 30.

Steps to Become Weasely
-Seek out and destroy every unique creature boss in every difficulty and slay them with Inferno (on Mag, Lit immunes), or Charged Bolt (on Fire, Mag immunes), Blood Star (on Fir & Bone Spirite, Lit immunes), or Golem (on triple immunes). Blood Star & Bone Spirit MUST be used if the monster is not immune to magic. No other spell may be used on these creatures (including Stone Curse). (This includes Diablo.)
-Find an item of Corruption and break it from full durability
-Wear only items that are indestructible while attempting to reach the stage of Weasel, except while breaking the Corruption item. (3 items of jewelry must be worn. Identification does not matter.)
-Have maxed resistances while attempting to reach Weasel.

Weasel
-You may buy books and elixers from Adria because you brought her fluids and knowledge from all the unique creatures you slew.

Enchantment restrictions

Predators
Fox, Jaguar, Eagle, Wolf, Tiger, Lion, Mammoth, Whale, Raven's, Snake's, Serpent's, Drake's, Dragon's, Hyena, The Vulture, The Jackal, of the Bear, The Leech

Vermin Haters
Soldier's, Lord's, Knight's, Master's, Champion's, King's (These noble and footsoldier types tend to put out traps for hapless rodents. Warrior's enchantment is fine because... well, warrior's are stupid and will speak to and accept anything: rocks, fish, corpses, etc...)

Unique Restrictions & Bans

Bans

Predators
The GRIZZLY, ShadowHAWK, DRAGON's Breach, The FALCON's Talon, GRYPHON's Claw, EAGLEhorn, Sharp BEAK

Nobility
OVERLORD's Helm

Items belonging to other Familiars
Rod of Onan, Barnard's Star, Hammer of Jholm

Restricted
Naj's Light Plate, Naj's Puzzler, Aguinara's Hatchet, Schaefer's Hammer, Civerb's Cudgel, Messerschmidt's Reaver. For more info on these, check the quest section.

Potion Restriction
You may not use elixers that were bought at Adria. If they WERE any good, don't you think she'd make them for you free of charge? You ARE her Familiar after all. Do not accept elixers as gifts unless you were on the level when it was found. Someone dropping an elixer in town does NOT count.
You may, however, use any other of Adria's potions. So why aren't Adria Potions banned? Because she works at making potions while YOU work at finding money. It's a way to make sure that she gets a profit.

Book Restrictions
-You may not buy books from Adria. Adria shares her books freely with you, her Familiar. If she had any books that would provide you knowledge, don't you think she'd have shared them with you? That she has! The only books that you may use must be found in the labryinth. Those books have knowledge that neither of you yet possess. (NOTE: You may only accept a book as a gift if you know for a fact that it was found on the level that you were on when it was dropped. Someone dropping an book in Town does *NOT* count as it being found on a level.)
-Further explaination: You are Adria's Familiar. She openly shares all the books that she has with you. You may not necessarily learn the spells, but you know the knowledge. Thus, these books have no value to you. You must learn spells either from A) Enchated Shrines B) Books found in the labryinth or C) Fascinating/Ornate/Sacred Shrines (although most would not go this last route).

Spell Restrictions
Fire: Guardian banned. Guardian is too much like another Familiar.
Lightning: Nothing banned
Magic: Golem banned. Bone Spirit banned. Golem and Bone Spirit are too much like other Familiars.
(NOTE: You must kill Golems made by other players. If they make Guardians, shoot them with a firebolt in protest for each one made. Same goes for Bone Spirits. These spells insult you. Be sure to tell others this so it doesn't look like you're crazy... or perhaps you want it that way :o]

Not all quests must be done, but the red lettered quests must be done and are listed first.

Quest: Prove yourself
The other townspeople don't like you, and they won't talk to you (except for Adria, of course). Prove yourself to them by defeating 8 different unique creatures in melee combat.
Reward
Move on to quest 2

Quest: Provide Food
The townspeople are glad that you are a nice little Familiar. They're hungary, however. You must feed them by showing them the Way of the Cow...
-Collect 3,000 gold. (Gold collected during Quest 1 does not count toward this total.)
-While still holding that 3,000 gold, touch an Enchanted Shrine.
-Go back to town without death and drop 1 pile of 1,000 gold in front of each cow and leave it there until that particular game closes.
The cows will eat the gold as if it were grain and begin producing milk. The enchanted gold works as a kind of, perhaps, Lactation Laxative? *MOO*
Reward
The townspeople will be happy with their newfound food. You may now use townspeople. You may NOT, however, recieve Free Healing from Pepin yet. He's not a veterinarian.

Quest: Messerschmidt and the Reaving
Adria tells you lore of the evil Familiars that lurk within the Catacombs. They were once honorable Familiars belonging to various mages of the Horadrim, yet they now are under the control of the Dark Lord of Terror. She tells you that the only way to destroy them is with the Messerschmidt's Reaver.
-Find Messerschmidt's Reaver and equip it. Ignore 2x str req in regard to Messy.
-Equip 3 items of jewelry that are of either "The Heavens" or "The Zodiac."
-Equip the Reaver, but take off your helm and armor.
-Go into the Catacombs and slay 4 levels that contain familiars using the Reaver as your only weapon. (You will need to do multiple games of Catacombs.) You may not use offensive spells (i.e. ones that dish out damage) on levels with Familiars.
Reward for Normal Difficulty: Familiar of Flame
Reward for Nightmare: Familiar of Hellfire
Reward for Hell: Familiar of Armageddon

1) The Quest to find Naj
Adria seeks the spellcaster, Naj. His legendary plate and staff are noted to be very powerful. If you should find both of them, take them to Adria.
-Take both the Naj's Light Plate and Naj's Puzzler to Adria -Adria will look over the trinkets and tell you that Naj's mind was tainted by Diablo and he became a Mage Demon.
-Kill the vile mage demons that tainted the mind of Naj (preferably on Hell diff, but may be elsewhere).
--Kill Dreadjudge by beating him to death with Naj's Puzzler
--Kill the Visier by beating him to death with fists while NPL equipped
--Kill Archbishop Lazarus by beating him to death (w/fists) while stark naked (itemless)
Reward
Naj has been avenged! You may use his items freely.

2/3) The Quest to find Civerb/Schaefer
Adria seeks the Cudgel of Civerb and Hammer of Schaefer. If you find either the Cudgel of Civerb or Hammer of Schaefer, take it to her.
Civerb's Quest
-Find Civerb's Cudgel
-Take it to Adria
-Learn that Civerb, once a mighty Paladin of the Zakarum, has fallen and had his form twisted into that of a goat. -Kill Deathshade Fleshmaul on Hell Difficulty using only the Cudgel and non-offensive spells.
Schaefer's Quest
-Find Shaefer's Hammer
-Take it to Adria
-Learn that Schaefer, once a mighty Barbarian of the Bear Tribe, was slain and his body possessed by Doomcloud.
-Kill Doomcloud on Hell Difficulty using only the Hammer and non-offensive spells.
Reward for Cudgel
Adria reasons that Civerb had been turned into a Goat or Horned Demon and that you may use the Cudgel.
Reward for Hammer
Adria reasons that Schaefer was turned into a lightning demon and that you may use the Hammer.

4) The Search for Aguinara
-Find Aguinara's Hatchet
-Take it to Adria. She explains to you that she was once an Amazon, and during those days she went by the name of Aguinara.
-Kill 12 unique creatures in melee combat while weilding Aguinara's Hatchet. Witchfire the Unholy, Witchmoon, Stareye the Witch, Bloodlust, Red Vex, Black Jade, and King Leoric must be among these 12. Only non-offensive spells may be used while battling these enemies.
Reward
You may use Aguinara's Hatchet freely.

5) Quest to Educate Pepin
-Find a Heal Other book and leave it at Pepin
-Find a "Sharp" non-blunt weapon OR the Black Razor OR the Bonesaw and leave it at Pepin
Pepin has been educated in the healing of small beasties.
Reward
You may use Pepin's Free Healing.