Mother of Dragons

When Mother of Dragons enters the battlefield,
create three 1/2 red Hatchling creature tokens.
At the beginning of your end step, put an Age
counter on each Hatchling you control.
{r}{r}, exile a Hatchling you control: Put a
Dragon creature from your hand onto the
battlefield with a converted mana cost less than
or equal to 3 plus the number of age counters
on the exiled creature.