Sacrificing a measly 1/1 to kill any creature or planeswalker is fantastic removal
As well as being able to swap what it's copying on your upkeep, this is also a may ability, so you don't have to
Some folks sell custom sets or run Kickstarter campaigns for entirely new expansions
A single stun counter will be removed if the permanent tries to untap for any reason, including its controller's untap step, a spell or ability trying to untap it, or even its controller trying to untap it to pay a cost (although that one's unusual)
It's also an efficient way to discard cards, especially if you're spending a mere 2 mana to escape it, making it a solid inclusion in Madness decks like Anje Falkenrath or Phoenix Tribal
Because you can use banked energy, this dinosaur is going to be a decent inclusion in EDH energy decks, as well