Not only is it a very powerful card that many control decks cant beat in long games, its also a card that is extremely really un-fun to play against
If another permanent would enter the battlefield under your control with one or more +1/+1 counters on it, the ability granted to that permanent by Cursed Wombat will trigger when that permanent enters the battlefield
This is especially important with Secret Lair, Universes Beyond, and premium variants
My sideboard was as follows: 4 Rest in Peace 1 Blood Baron of Vizkopa 1 Kaya, Orzhov Usurper 1 Despark 1 Rakdoss Return 2 Infernal Reckoning 2 Thoughtseize 1 Thought Distortion 1 Golgari Charm 1 Slaughter Games This sideboard targets graveyard decks like Soulflayer, Dredge-less Dredge, and Underworld Breach, along with Mono-Black Aggro, Izzet Ensoul, and Azorius Control
But Auger did see a fair amount of play, and this is both an otter and a wizard, so it has some good synergies