This one is called Ram Skull Gate (Grendel #10014).
This one is called Cyclops Skull Portal (Grendel #10054).
This one is called “Samwise Gamgee with Moria Mines Goblin battle action base” and it’s from the Lord of The Rings Movie Series 1 by Toy Biz in 2001. Of course, I removed Samwise because he was blocking the door, but don’t worry about him. He now lives with my daughter’s Barbies and is very happy.
This one is called Cyclops Gate (Grendel #10008).
This one is simply called Skull Gate (Grendel #10013).