Visit Fire Spirits to gain Server War scores. (Visit it on enemy server to gain more).
Whilst not technically a monster (far and away to cute to be a monster), because you don't kill these sweeties for rewards, you do still need to visit them to get rewards. They only appear during the server war (which occurs every second weekend) and are usually quite easy to find, scattered all over the server map.
A visit will cost you only 2 stamina and you can only visit an individual spirit once, but be warned, there is only a maximum of 3 claims per spirit and if you don't get there in time, you wont get your stamina back. And the rewards ... 1,500 points toward your server war score and 1 x Fire Spirit Chest (refer to Common Items for more details). If you find and visit a Fire Spirit on the enemy server, you will earn yourself 2,400 points and 1 x Fire Spirit Chest (plus the bonus of using up one of their visits).
Even though they don't provide a large number of points, it is possible to visit a large number and it is amazing how the points will build up. By visiting lots of spirits you will be adding to the total server score and have the added bonus of loads of chests at the end of the war.