Sphyrna-Class Hammerhead

Flying, Trample.
If Hammerhead-Class Cruiser would die,
instead exile it with three fuel counters on it.
At the beginning of your upkeep, if Hammerhead
is exiled with a fuel counter on it, remove a
fuel counter from it.
Then if Hammerhead has no fuel counters on it,
return it to the battlefield.