What dragons? The player characters can spawn in the RTS portions by hitting 'R' (after a couple minutes into the battle); other dragons could show up in the single player campaign.
Ah, there we go. They need to make that WAAAAY more obvious. Neither my friend nor I were aware of such functionality and played without ever pressing R (outside of the first few seconds). There should be an icon to click with the hotkey on top of it.
