1) it introduces the mouse on land with directly telling readers a mouse had unfortunationly made a misake of friending the frog, who lived in the water.
2) The shocking conflict and event of the frog tieing the foot of mouse to it's own to search for food but this soon will be a big mistake.
3) the frog without consent of the mouse jumped in the water, drowning and killing the poor mouse.
4) the hawk witnessing the murder to then do a good deed.
5)the hawk as an unconscious act of avengement kills the frog