Weird Lines

[DarthVader12]

What are those? They appear with creeper. It turns white with anti-creeper.

[mthw2vc]

That is the minimap, you can use it to keep track of any creeper of any sort at any elevation on the map. It also has special symbols to indicate emitters, or any other hazards you may run into... ;)

[Fisherck]

Very helpfull, especially in the case of entombed creeper like in cubic (see here).