Diablo II/Enemies

Superior/Champion

 * Champions
 * Possessed

Act I
The forest and plains act; Act I contains the weakest of all the enemies. It isn't so much themed as really diverse in what creatures reside in it. Demons, skeletons, and beasts are all pretty equal in terms of population, however each is more common in various areas (this is common to both Diablo and Diablo II).

Zombies
Zombies >> Hungry Dead
 * Undead

Zombies are the second weakest enemy in the game, they are slow, they have a much higher maximum health than quill rats, and have a strong (again slow) melee attack. Unique zombies can sometimes be a hassle depending on their special traits, i.e. cold enchanted and extra strong can cause them to be over powered.

Quill Rats
Quill Rats >> Spiked Fiends >> Thorn Beasts >> Razor Spines

Fallen
Fallen >> Carvers >> Devilkin >> Dark Ones
 * Demon

Uniques

 * Rakanishu: Lightning Enchanted

Fallen Shaman
Fallen Shaman >> Carver Shaman
 * Demon, Raises dead of the same species (Fallen, Carver, etc.)

Gargantuan Beasts
Gargantuan Beasts >> Brutes

Gargantuan Beasts can be found in the Blood Moor, and Den of Evil. Brutes are found within the Black Marsh.

Uniques

 * Treehead Woodfist: Extra Strong, Extra Fast

Skeletons
Skeleton >> Returned
 * Undead

Uniques

 * Black Hawk
 * Puke Maw
 * Bone Drinker

Skeleton Archers
Skeleton Archers
 * Undead

Uniques

 * Dragon Jade The Jagged

Dark Rangers
Dark Ranger
 * Demon

Dark Hunters
Dark Hunter >> Vile Hunter
 * Demon

Vile Hunters are found in the Dark Wood.

Dark Spearwomen
Dark Spearwoman
 * Demon

Moon Clan (Goat Men)
Moon Clan >> Night Clan
 * Demon

Misshapen
Misshapen >> Tainted >> Plaguefiend
 * Demon

Special Uniques

 * Griswold: Undead, Cursed
 * Blood Raven
 * Andarial

Act II
While Act I may be an environment that is very grassy, Act II is much more arid and desert like. The creatures found here range from sandy beasts to mummified undead and finally to anthropomorphic snakes and cats.

Cliff Lurkers
These are the basic type of this enemy. They look like a skinny frog with a rough, almost rock like hide. Cliff Lurkers and their successors are very quick and are characterized by their leap ability, which they use randomly and only sometimes for attack. Their attack is much lower than other enemies, but they have a high amount of health.

Claw Vipers
An aggressive species of man-like snakes. Unlike normal serpents, Claw Vipers slither upright and have arms.

Catgirls
There are ones with whips, ones with javalins, and ones that toss poison gas containers.

Maggots
Sandworms >> Rockworms
 * Demon

Scarabs and Beetles
Scarabs/Death Beetles
 * Demon, Lightning Enchanted

Special Uniques

 * Radament
 * Coldworm the Burrower:Cold Enchanted, Magic Resistant, Immune to Cold
 * Duriel

Flayers
Flayers >> Undead Flayers >> Undead Soul Eaters?

Flayer Shaman
Flayer Shaman

Frogs
Frogs >> Slime Princes

Sextants
Sextants >> Cantors >> Heirophants

Drowned Carcass
Just like the basic zombies, although with much higher damage and health.

Special Uniques

 * Mephisto

Flesh Beasts
Flesh Beasts >> Stygian Hags

Flesh Spawners
Flesh Spawners >> Stygian Dogs

Special Uniques

 * Izual
 * Diablo