Monster Animals

I have had Echo here for a few days. He eats things. Not just food but things. He also is a hole digger. I have two devils in the house.
I kind of figured he would keep cats out of the yard. I thought he would eat Logan. I wasn't here for the first initial response. When I got home, Logan found himself a hiding spot under the bed. He would growl to the point I thought someone had their phone on vibrate. It might not be the best idea. Logan will run under the TV in the living room. Echo nearly knocked the TV off the entertainment center.
I think Logan likes to torture dogs. He has not been declawed...yet. The first night Echo stayed in his kennel and Logan was out and about. He crept up on the dog. I didn't know what was going on but Echo would not be quiet.
The next night I attempted to let them both out. That didn't last very long. Logan cornered Echo and was swatting the poor puppy in the nose.
Echo will chase the kitten all over the house. Logan will antagonise him. He will arch his back and get all poofy and walk sideways.
The boys had a pissing contest in the house. Poor Frank will get trampled all over and starts acting like a wuss.
It's starting to mellow out gradually. I keep finding pieces of toys everywhere. Echo seems to think he is a cat and eats the cat toys. He ate two rawhide bones. I don't understand why he won't eat his own toys.