Spara's Bodyguard

When Spara's Bodyguard enters the battlefield,
you may put a shield counter on it.
As long as Spara's Bodyguard has no shield
counters on it, other nontoken creatures enter
the battlefield under your control with an
additional shield counter on them.
At the beginning of each combat, Spara's
Bodyguard gets +1/+1 for each shield counter
among other creatures you control.