I've searched the wiki and went to the search bar.

The wiki showed one script that was for walking:

 Game.Players.PlayerAdded:connect(function(player)
	while not player.Character do wait() end
	local character = player.Character
	local animateScript = character.Animate
	animateScript.idle.Animation1.AnimationId = 'http://www.roblox.com/asset/?id=161100084'
end)

and

Game.Players.PlayerAdded:connect(function(player)
	while not player.Character do wait() end
	local character = player.Character
	local animateScript = character.Animate
 
	-- Create instance for new animation
	local newFallingAnimation = Instance.new("Animation")
	newFallingAnimation.Name = "FallAnim2"
	newFallingAnimation.AnimationId = 'http://www.roblox.com/asset/?id=165167632'
	newFallingAnimation.Parent = animateScript.fall
	end)

Help? Please, maybe, list types by editing the scripts? Oh, and I'm sorry for asking a bunch of questions. I'm just curious how it works.

http://wiki.roblox.com/index.php?title=Changing_default_character_animations