Water
The only mob that can spawn in water is currently a squid.
no, that is why they still spawn and despawn in 1.2
You can only spawn mobs in creative mode, where they give you spawn eggs. if you use a squid spawn egg in water, a squid should appear.
You have to be in the Hell biome and the ghast needs a 5x5x5
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
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.
You can't spawn in a farm. You make one.
In creative mode you can spawn a zombie with the egg
Yes, villages spawn in the 1.0.0 release of Minecraft. They were originally added in version 1.8
Minecraft originally came out with spawn eggs in a pre-release - 11w49a. The update was for Minecraft 1.1, in case you are looking for an actual Minecraft update release.