There's no such in-game definition as a Legendary dragon. Normal dragons are ranked as Dragon, Blood Dragon, Frost Dragon, Elder Dragon and Ancient Dragon, the last of these starting to appear at about character level 45.
My recommendation is that you should do it around level 50. But only if you have good amour.
his name is evlarg but his level is 83
If your talking about the Dragon Slayer in Adventure Quest then it's called Guardian and yes you do. Scholar and Fighter both have to reach level 10 before you can exceed in the Dragon Slayer Class. As a Normal User your Class can only reach 5 MAX.
The only f2p dragon is the one from the quest "dragon slayer".
You must be a level 37 dragon slayer.
The minimum requirement is level 20 I believe.
Providing you have brought and anti-dragon shield that you must obtain as part of the quest, then a level 71 should have no bother killing Elvarg if they bring decent food.
Yeah almost everyone who reaches level 40 does that quest.
I would train a little bit more until you are around level 50, before you start doing that quest, train your strength and defence up.
You don't to be a specific level to be a dragon-slayer. You just need to go talk to Galanoth the Dragon-slayer Master in Vasalkar Lair in Skullholme. I recommend you go there when you are at level 8 or higher. Also, bring friends to help you kill the red dragon when you go on the final quest because you need to kill it 8 times.
If a level 3 can complete dragon slayer, then yes u can beat i the dragon with *36att 39str 36def & 39mage*
If your talking about the quest, you kill wverns and Water draconians. If your talking about dragon slayer class, that's a rank and if you want to rank it up, I suggest undead pirates
ANSWER #1:YES! You can kill a green dragon at that level just remember to bring your anit-dragon shield (if you don't have one you can get them from the G.E or from the duke of lumbrige as long as you have done dragon slayer) and some food I recommend lobsters at you're level.