Wierd Arrow in minimap.

[durecellrabbit]

I was riding through ronfare when I noticed a red targeting arrow on my minimap. I went to check it out but all I could find was a guy fighting a rabbit, he killed it and it said I gained no exp and the arrow went away. Does anyone know what the arrow was for and what the no exp thing was as well?

[Tirrock]

He had called for help. That allows anybody to fight it, and let's people nearby know where the monster the player had called for help on is.