You can either use mob eggs, single player commands, or GUI Spawner Mod.
You can download a mod so you can place mob spawner blocks in creative. But that's the only way unless there is a hack at which you can
You can get a mob spawner in Minecraft by using any pickaxe (except wood) with Silk Touch 1 enchantment or by spawning it in (Dec:52).
By using single player commands. being OP on a server OR by placing a mob spawner, achievable through mods/mcedit.
You can't mod Minecraft PE, there's no way to add Herobrine into it.
You need to find a dungeon which has a mob spawner inside. (It looks like a little cage with fire and a miniature version of the mob it will spawn.) Mob spawners can spawn in dungeons zombies, skeletons or spiders. In abandoned mine shafts they can spawn cave spiders. In strongholds they can spawn silverfish. In Nether Fortresses they can spawn blazes.
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.
You cant find a giant mob in vannilla minecraft but you can sumon him using a command or a spawner.
that depends on the version and edition of minecraft you are playing.
It is not possible to actually make a mob spawner in any version of Minecraft. Mob spawners are only obtainable via in-game commands or if you use a mod of some sort.
No, the AI for mobs in minecraft has been improved so mobs don't spawn in strange places. You can manually spawn them in lava with that mob's egg.
Nothing! You do get some XP though, and the mobs stop spawning, but you cannot obtain the spawner.