Elder DragonDragons play a big role in Skyrim. For starters, you play a Dragonborn. But bigger than that, Skyrim marks the return of the majestic creatures as prophesied by earlier entries in the series, when the Staff of Chaos was shattered in The Elder Scrolls: Arena, when the Numidium appeared in Daggerfall, by Red Mountain in Morrowind, and the opening of the Oblivion gates.
At the beginning of Skyrim, lesser dragons are roaming the world, and the player will encounter them all throughout the game in battle and during various scenes.
Dragons can be randomly encountered throughout Skyrim, and are said to respawn endlessly (but not constantly) to give players the impression they cannot stop the threat of dragons before the end of their quest.
When dragons breathe ice or fire down upon their enemies, it's said that they're speaking in an ancient tongue. When dragons fight together, it's really only a brutal, verbal debate.
Defeating dragons will be the key to unlocking new Dragon Shouts that the Dragonborn will be able to use. The Dragonborn can even forge new sets of armor using parts acquired from dragons they defeat.
The corpses of dragons you defeat can be looted as a result, and generally drop a few bones, scales, gold, and gems. However, in the PC version of Skyrim, the dragon bones never disappear from the overworld, due to a glitch that Bethesda may or may not fix.
The Dragons are returning after being brought back to life by Alduin, the brother of Paarthurnax. The player first sees this after meeting with Delphine, one of the last surviving members of the Blades, when they travel to Kynesgrove and see him resurrect a lesser Dragon called Sahloknir.