How do we get really strong monster like on the cover of the gam

I don't know for shure but I think that you have to unlock monster areas and to do that you have to get marryied ,have a baby,build a school,and then after that you turn into your child and then when you go in front of it you have to do what it saysthen it is unlocked

Ok, I'm assuming that you're talking about the Dragon-looking thing, so here goes.
That dragon is a monster that is in the last dungeon, at the end of the game(but it's not the final boss). You need to become a kid, get all the tablets, upgrade your farm all the way, and get a spell from the school(after it's upgraded, and you gotten all the tablets). I think the spell is called something like dragon rage, but I'm not sure. Then you go to the mayor and have him uprade your barn for the last time (28 or 26 floor I think). The entrance to the last dungeon is in the bottom floor.
*phew*... That's a mouthful, but not even half of it.. It's just an outline.. If you want really specific details, find a game guide somewhere on the internet, and look how to unlock the last dungeon... I think there's a guide on this site.

You can't befriend Fiersome he's a dragon god and you have to defeat him to be able to find your dad.