They allow Zombies to be cast repeatedly from the graveyard, ensuring steady board presence and which makes the deck highly resilient against removal and repeated board wipes
Often as part of event promotions, holiday giveaways, or post-maintenance compensation
Serperior is also potentially good with the currently strong Venusaur ex deck, although it could take a while to evolve both Pokemon fully
Be sure to let us know which cards youd like to see removed, as well as anything else ban list adjacent, in the comments or over on the Draftsim Discord
They are a fairly painless splash and can be done with far less fixing than other splashes with them not resulting in a dead card without the mana to activative them.
C Common Playful Possum X EARTH Level 2 [ BeastEffect ] ATK 800 DEF 600 During your Main Phase: You can destroy this face-up card on the field