Evolved Spinoderm enters with four oil counters on it.
Evolved Spinoderm has trample as long as it has two or fewer oil counters on it. Otherwise, it has hexproof.
At the beginning of your upkeep, remove an oil counter from Evolved Spinoderm. Then if it has no oil counters on it, sacrifice it.
If Evolved Spinoderm somehow loses all of its oil counters due to an effect other than its upkeep triggered ability, this won't cause its controller to sacrifice it until the next time its upkeep triggered ability resolves.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.