THE REAL FULL LIST OF BREEDING COMPOSITION

This forum is a crazy mess of suggestions, thoughts and actual knowledge. What I am showing you now isn't guesswork - this is the full list of breeding options in Master Breeders 3.7.
Though many people have posted partial lists, I've double checked every matchup. Credit for some of the specials go to other people on the board, but a majority of them were found through trial and error.
Please do not take the work here and put it on another thread. I spent several hours acquiring this information, so please don't reformat it and call it new. If you have any revisions, please post mistakes/comments/combos in reply to this topic. I will update the list.
Guideline:

• E = Earth
• F = Fire
• H = Holy
• L = Lightning
• M = Metal
• U = Unholy
• W = Water
  
• (* indicates a Gold monster, that is done evolving)
  

Tier 2
EF - Fire Weed
EH - Hippy
EL - Lightning Lizard
EM - Solid Golem*
EU - Evil Tree
EW - Mud Monster
FH - Burning Light*
FL - Flash Fire
FM - Overheated Machine
FU - Burning Dead
FW - Steam Being*
HL - Holy Bolter
HM - Blessed Construct
HU - Zombie Paladin*
HW - Illusion
LM - Ground Charger
LU - Relentless Dead
LW - Wet Current
MU - Cursed Construct
MW - Slippery Machine
UW - Drowned Soldier*

Tier 3
EF+EW - Flamming Rock
EF+FL - Pyromancer
EF+HL - Horned Beast
EF+HW - Kobald
EF+LU - Ghast
EF+LW - Tri Elemental
EF+MU - Chaos Machine
EW+FL - Crusty Crab
EW+HL - Mystic Frog*
EW+HW - Sea Troll
EW+LU - Storm Summoner
EW+LW - Sea Turtle
EW+MU - Bone Dragon
FL+HL - Holy Purger*
FL+HW - Hydromancer
FL+LU - Goo
FL+LW - Sea Dragon
FL+MU - Molten Warrior
HL+HW - Tornado
HL+LU - Lightning Dragon
HL+LW - Electric Eel
HL+MU - Furbolg
HW+LU - Hydro Zombie
HW+LW - Magician
HW+MU - Flying Naga Chick
LU+LW - Lightning Demon
LU+MU - Quad Death*
LW+MU - Mammoth

EH+EL - Savage Shrub
EH+EU - Dark Hippy
EH+FM - Gold Lizard
EH+FU - Blazin Hippy
EH+HM - Priestess of the Light
EH+LM - Toxic Spider
EH+MW - Treant
EL+EU - Moss Monster*
EL+FM - Fire Snake
EL+FU - Wild Murlock
EL+HM - Mage Stalker
EL+LM - Super Charger*
EL+MW - Sparking Lizard
EU+FM - Lava Runner
EU+FU - Strangling Dead
EU+HM - Vampire
EU+LM - Chaos Vine
EU+MW - Over Grown Hedge
FM+FU - Searing Dead
FM+HM - Mecha Pig
FM+LM - Molten Machine
FM+MW - Tempered Mech
FU+HM - Lesser Alien
FU+LM - Wraith
FU+MW - Diffusional Monster*
HM+LM - Battering Ram
HM+MW - Rain Mauler
LM+MW - Seige Engine

Tier 4
[EF+EW][FL+MU] - Flamming Knight
[EF+FL][FL+HW] - Dualmancer
[EF+HL][EF+HW] - Rabid Beast
[EF+LU][HW+LU] - Apperation
[EF+LW][EL+FU] - Mirrored Murlock
[EF+MU][FM+MW] - Master Mech
[EW+FL][FL+LW] - Sea Monster
[EW+HW][EW+LW] - Ocean Warrior
[EW+LU][LU+LW] - Static Conductor
[EW+MU][HL+LU] - Black Dragon
[FL+LU][FU+HM] - Greater Alien*
[HL+HW][EH+HM] - Priestess of the Sky
[HL+LW][EL+FM] - Elemental Worm
[HL+MU][LW+MU] - Giant Beast
[HW+LW][EL+HM] - Anti Mage
[HW+MU][HM+MW] - Lock Ness
[EH+EL][EU+MW] - Spawn of Nature
[EH+EU][EH+FU] - Super Hippy
[EH+FM][EL+MW] - Joo Lizard
[EH+LM][EU+FU] - Toxic Death
[EH+MW][EU+LM] - Force of Nature
[FM+EU][EU+HM] - Ancient Vampire
[FM+FU][FU+LM] - Phoenix
[FM+HM][FM+LM] - Mechanicle Monstrosity
[HM+LM][LM+MW] - Diabolical Machine

Tier 5
[EF+EW][FL+MU]+[FM+FU][FU+LM] - Fire God*
[EF+FL][FL+HW]+[EW+MU][HL+LU] - Crimson Dragon*
[EF+HL][EF+HW]+[HL+MU][LW+MU] - Beast of Destruction*
[EF+LU][HW+LU]+[EH+EL][EU+MW] - Unsealed Evil*
[EF+LW][EL+FU]+[HW+LW][EL+HM] - Master Assassin*
[EF+MU][FM+MW]+[FM+HM][FM+LM] - Ancient Construct*
[EW+FL][FL+LW]+[HW+MU][HM+MW] - Water God*
[EW+HW][EW+LW]+[FM+EU][EU+HM] - Chosen Warrior*
[EW+LU][LU+LW]+[HL+HW][EH+HM] - Lightning God*
[HL+LW][EL+FM]+[EH+FM][EL+MW] - Insane Serpant*
[EH+EU][EH+FU]+[EH+MW][EU+LM] - Eternal Force*
[EH+LM][EU+FU]+[HM+LM][LM+MW] - Undead Machine*

Specials
{[EF+EW][FL+MU]+[FM+FU][FU+LM]}+{[EW+FL][FL+LW]+[HW+MU][HM+MW]}+{[EW+LU][LU+LW]+[HL+HW][EH+HM]} - Mike Hill (All Tier 5 Gods)
{[EE]+[FF]+[HH]+[LL]+[MM]+[UU]+[WW]}+{[EF+LW]+[EF+LW]+[EF+LW]} - Supreme Elemental (Rainbow + Ownage Elemental)
[EE]+[FF]+[HH]+[LL]+[MM]+[UU]+[WW] - Ownage Elemental
[FL+LU][FU+HM]+[EH+FM][EL+MW] - Josh
[EF+LW]+[EF+LW]+[EF+LW] - Rainbow Elemental
[FU+HM]+[EU+LM]+[EH+LM] - Alien Tentacle
[LU+MU]+[FU+LM]+[FL+LU] - Oquies
[FL+HL]+[EH+HM]+[HW+LW] - Holy Ghost
[EW+HL]+[EL+FM]+[FL+LW] - Hydra
[EU+FM]+[EL+LM]+[HL+HW] - Nightmare
[EL]+[LW]+[FH] - Hyper Charge
[EH]+[EH]+[EH] - Secret Hippy

The specials section isn't completely complete, I'm sure! So if you find another combo, post here and we'll look into it.
Got a question? Ask me here or on B.Net server Azeroth (US East) under the username "Atriz".