this Pokmon does 20 damage to itself when the attack is used
Krark, the Thumbless is a partner commander that gets up to some nasty business with spellcasting payoffs like Guttersnipe and Fiery Inscription
Now, onto the card itself, it's shite, as said before, destroy your extra deck for some random Xyz / Fusion / Synchro that will not be good enough in the long run regardless of what you're Summoning
1 Unseal the Necropolis
You also get all the cards you attached to them back to your hand, which is good for tactical plays and recycling resources
The good news is that protecting a card properly costs cents, not dollars, and it greatly reduces returns and buyer complaints, and possibly gives you negative feedback, ruining your eBay profile