You can't. There are two minecraft demos that I know of: one on minecraft.net, and the PC Gamer demo. Both are locked in survival mode, and in survival mode there is no way to spawn mobs.
Sorry no, you cant.
Yes, pigs are available/roaming in Minecraft classic.
if you mean a mob spawner, which has a pig on fire in a cage block, you have to set the game difficulty to easy, normal, or hard. it will spawn mobs about every 21 seconds in a 9x9x9 area if there is a logical place to spawn a mob. if there are no logical places to spawn a mob, it will spawn nothing until an area opens up.
The only way to spawn herobrine in minecraft is to use mods as you cannot spawn him in vanilla minecraft.
A dungeon in Minecraft can spawn on any level that normal land can spawn on
You can watch a minecraft game demo at youtube or dailymotion.
Wolves will sometimes spawn in forests in Minecraft PE 0.9.0 and above.
No, currently in vanilla Minecraft dinosaurs are not in the game. This means there are no spawn eggs for them.
there is no demo version, though
No you just log in and play the demo
No
The similarities of Survivalcraft demo and minecraft PE are: Their function, and two modes.