Unidentified forest egg

Unidentified forest egg enters the battlefield with
x permanent strength counter on it.
{1}{g}: Put one permanent strength counter on unidentified forest egg.
When unidentified forest egg has 6 or more
counters on it exile it remove half the permanent strength
counter rounded up and return it to the battlefield transformed.
Hatchery(can be a commander with any number of creatures with hatchery)