Off you idea
Goblins:
Spring Camp near rivers to celibate spring time and collect water and make river wine (mostly for trading).
Summer They travel from area to area to attack near by cities and towns. They are very active in this season.
Autumn They return to the swaps or deep forests and feed off the foods and other supplies they took during the summer.
Winter They are rare and never seen outside their areas they control. They may attack a city in the winter if they are paid to do so by another city or lack of worshiping a god or they have ran out of food and other supplies.
“We come, we take, we leave, you quake!” - Goblin King Juxrin
What do you guys think?