My Dwarf Gourami is picking on my new Red Tail Shark!?

Give it a little time. If the Red Tail Shark's fins start looking torn and ripped, it is best to separate them. If he keeps coming out of his ornament, he probably isn't as intimidated as you think. In a couple days the Gourami should settle down and get use to the new guy. You'd think fish would get bored when kept alone and enjoy company after such a depressing time. Fish go purely by nature and Gouramis can be aggressive. I doubt the Red Tail Shark will fight back now. They become more aggressive when 3-4". Some people keep little 1-2" ones in community aquariums even.