Child of the Ur-Dragon

Flying
{w}: +0/+1 until end of turn
{5}{u}: Unblockable until end of turn
{2}{b}: Regenerate Child of the Ur-Dragon
{r}: +1/+0 until end of turn
{3}{g}: Trample until end of turn
Whenever another Dragon you control attacks, Create a token that's a copy of that dragon that's tapped and attacking. Sacrifice that token at the end of combat.