If you approach a creeper, it will start to follow you. If it gets too close it will explode and you'll lose a lot of health, or die if you are too close (even if you are invisible). You know when they are about to blow up when they start hissing and will started flashing. However, if you run back, and then foward, striking it every time you run at it, it will eventually die and have a chance drop gunpowder. Do keep in mind that creeper explosions can also destroy blocks so if you have one near your house and it sees you, it's best to run away.They only spawn in night time.Also remember never to dig straight up! A creeper can easily come right next to you and explode when you are looking up. For some reason whenever I look up, a creeper always decides to spawn and explode... You can wear enhancements (Blast Proctection) on your armor to be more resistant to creeper explosions. Creepers are not undead mobs, so Splash Potions of Harming will kill them. If you want the creepers and other mobs that kill please turn on peaceful but you can not turn in hardcore so beware.
No, Creepers just flee from them.
Yes, creepers were an error, they messed up a pig...
Nothing.
No, Creepers do not burn, the sun burns undead such as Zombies and Skeletons.
Creepers and Ghasts will sometimes drop it when you kill them.
There aren't "ancient creepers" in the application version of Minecraft, there are creepers.
It's called Minecraft... creepers have ALWAYS been in Minecraft.
No, Creepers just flee from them.
Yes, creepers were an error, they messed up a pig...
Yes
No hostile mobs (including creepers) are present in peaceful difficulty.
Yes
Yes, they will explode.
Nothing.
They explode once they sees you.
Kill Creepers.
Yes