Attack Name	Battle Type	Contest Type
Overheat
Power Points	Base Power	Accuracy
5	140	90
Battle Effect: Allows a full-power attack, but sharply lowers SP. ATK.
Secondary Effect: Lowers user's SP. ATK two stages.		Effect Rate: 100 %
TM #	Appeal Points	Jam Points
TM50
Contest Effect: After this move, the user is more easily startled.
BrightPowder	King's Rock	Physical Contact
Yes	Yes	Yes
Battle Palace Style	Battle Arena	Pokémon Hit in Battle
Attack	+1	Selected target
Picture Example of Overheat

Pokémon That Learn Overheat By Level Up in Ruby/Sapphire/Emerald/Colosseum/XD:

Pokémon That Learn Overheat By Level Up in Fire Red/Leaf Green:

Pokémon That Learn Overheat By TM:

No.	Pic	Name	Type 1	Type 2
#004		Charmander
#005		Charmeleon
#006		Charizard
#037		Vulpix
#038		Ninetales
#056		Mankey
#057		Primeape
#058		Growlithe
#059		Arcanine
#077		Ponyta
#078		Rapidash
#136		Flareon
#146		Moltres
#151		Mew
#155		Cyndaquil
#156		Quilava
#157		Typhlosion
#209		Snubbull
#210		Granbull
#218		Slugma
#219		Magcargo
#228		Houndour
#229		Houndoom
#250		Ho-oh
#255		Torchic
#256		Combusken
#257		Blaziken
#294		Loudred
#295		Exploud
#322		Numel
#323		Camerupt
#324		Torkoal
#338		Solrock
#383		Groudon
#384		Rayquaza

Pokémon That Learn Overheat By Breeding:

Pokémon That Learn Overheat By Purifying or A Special Way: