Dragonscale Sliver

When Dragonscale Sliver enters the battlefield,
put a +1/+1 counter on each Sliver.
Whenever a nontoken Sliver dies, its controller
may put a 0/0 colorless Sliver creature token
onto the battlefield tapped, then put a +1/+1
counter on it.
"All Slivers are family." - Anafenza, the Foremost