Eldon Tyrell, Nexus Architect

Each Replicant you control enters the
battlefield with an additional +1/+1 counter on
it for each Replicant you already control.

{t}Create a 1/1 colorless Replicant Owl token
with Retire 1. (This creature enters the battlefield with one time counter on it.
At the beginning of your upkeep, remove
a time counter from it. When the last is
removed, sacrifice it.)