The quest is called "Training". It teaches you how to get stronger and better when you go into battle with frogs, sharks, etc... While I did this quest, a shark told me that I had to find this rat. I followed the arrow to where I was supposed to go. I went into this little room to find the rat. I went to this man to ask where the rat was. I followed his directions and went downstairs. I went down and saw him. We all went into battle in the middle of the battle the rat fled and we had to finish the battle by ourselves. All the rats were defeated.