Next keep your summon out while you are hunting yourself, the summon will get a portion of the experience you will get while hunting. It's recommended to level your Evil Raccoon to at least level 20-25 like this before you start evolving it.
Note that each summon has a certain amount of SPT (Spirit Time), when this time runs out, your summon will be dismissed for a certain time to regain SPT. The higher evolution level your summon is, the higher the SPT will be.