Sparkmite Migration

When Sparkmite Migration enters the battlefield,
create two Sparkmite tokens. (They're red 1/1
Elemental creature tokens with "Whenever this
attacks and isn't blocked, it gets +1/+0 until end of
turn".)
Whenever two or more Elementals you control
attack, create a Sparkmite token that is tapped
and attacking.
The mites' flight marks the imminent coming of winter.