Dagannoth Rex
Apparrently yes; check this: http://runescape.wikia.com/wiki/Dragon_hatchet However, if you specifically want a dragon hatchet, it would be better to just buy it.
the second floor of runescape has a npc walking around with it talk to him he will hand you one.
Clue Scrolls, NPC drops, Grand Exchange, player trading and many other methods.
An NPC in Burthorpe.
There is no NPC, place, or item in RuneScape called "Kela."
On the mountains, north of the dwarven mines. The "Oracle" is an NPC, a lady that walks around over there.
Go buy one from a NPC.
Moparscape client should have a basic NPC list built in.
No, but only certain NPC's, monsters will drop them.
Realistically, you have 3 choices; 1) Buy it from the Scimitar shop in Al Kharid 2) Get it as a drop from an NPC that drops it 3) Buy it from the Grand Exchange
From a stall NPC in Al-Kharid
An NPC is a non-player character. Basically anyone who is isn't controlled by a player (Romeo in Varrock, Varrock guard).