Nature
Air = Starting element
Ash = Fire + House
Earth = Starting element
Energy = Air + Fire
Fire = Starting element
Lava = Earth + Fire
Metal = Stone + Fire
Steam = Water + Fire
Stone = Water + Lava
Water = Starting element
Animals
Bat = Vampire + Air
Beast = Starting element
Dove = Rat + Air
Egg = Magic + Stone
Fish = Beast + Water
Piranha = Fish + Weapon
Rat = Beast + Diseases
Snake = Egg + Worm
Wolf = Beast + Wrath
Worm = Magic + Man
Evil
Chaos = Starting element
Darkness = Starting element
Death = Human + Life
Diseases = Tobacco + Man
Inferno = Human + Murder
Magic = Demon + Energy
Sect = Heresy + Religion
Sin = Human + Apple
Styx = Water + Death
Suffering = Fire + House
Good
Angel = Life = Light
Friendship = Human + Human
Heavens = Fire + Witch
Life = Man + Woman
Light = Starting element
Order = Starting element
Prayer = Angel + Human
Religion = Human + Prayer
Resurrection = Soul + Corpse
Soul = Demon + Human
Technology
A.I. = Computer + Life
Car = Oil + Mechanism
Cellphone = Radio Wave + Computer
Computer = TV + Book
Cyborg = AI + Robot
Electricity = Energy + Metal
Internet = Computer + Computer
Radio Wave = Electricity + Air
Robot = Mechanism + Computer
TV = Mechanism + Demon
Humans
Blood = Weapon + Beast
Corpse = Human + Murder
Food = Weapon + Beast
Human = Starting element
Lawyer = Human + Copyright
Politician = Human + Pride
Man = Starting element
Sekz = Man + Woman
Witch = Woman + Magic
Woman = Starting element
Monsters
Cerberus = Beast + Death
Cthulhu = Demon + Water
Demon = Beast + Darkness
Dragon = Magic + Egg
Frankenstein = Corpse + electricity
Hydra = Snake + Beast
Mutant = Human + Darkness
Vampire = Blood + Human
Werewolf = Man + Beast
Zombie = Life + Corpse
Plants
Apple = Starting Element
Coffee = Seeds + Energy
Grass = Earth + Seeds
Mushroom = Earth + Seeds
Seeds = Apple + Earth
Tobacco = Grass + Fire
Tree = Earth + Seeds
Sins
Envy = Sin + Greed
Gluttony = Sin + Food
Greed = Sin + Money
Heresy = Religion + Sin
Lust = Sin + Sekz
Murder = Sin + Corpse
Pride = Sin + Sin
Sloth = Sin + Work
Theft = Sin + Money
Wrath = Sin + Weapon
Society
Atheism = Human + Heresy
Book = Human + Knowledge
Censored = Mechanism + Sekz
Copyright = Demon + Order
Gambling = Human + Greed
Knowledge = Human + Apple
Money = Soul + Demon
Psychology = Human + Heresy
War = Politician + Pride
Work = Man + Money
Tools
Acid = Water + Sulfur
Bomb = TNT + Metal
House = Stone + Human
Mechanism = Metal + Work
Nuclear Bomb = Bomb + Mushroom
Oil = Earth + Knowledge
Poison = Tobacco + Coffee
Sulfur = Inferno + Air
TNT = Oil + Acid
Weapon = Human + Metal
All of the combination of elements shown in the Doodle Evil walkthrough can be done with trial and error.