[Eryops]

If you're using the Princess and Dragon expansion (and probably have it if you're going to buy this expansion) then having the dragon on the board right off the bat (due to the final volcano tile) is important. There's nothing like laying out the river and the first tile drawn is a dragon tile and he moves up the river gobbling up meeples. This river aspect changes the dynamic of the game more than anything else where you could wait 30+ tiles before drawing a volcano and getting the dragon on the board.