Primordial Ooze attacks each combat if able. At the beginning of your upkeep, put a +1/+1 counter on Primordial Ooze. Then you may pay {X}, where X is the number of +1/+1 counters on it. If you don't, tap Primordial Ooze and it deals X damage to you.
![Primordial Ooze [Chronicles]](http://www.cardmerchanttakapuna.co.nz/cdn/shop/products/de325157-6bcc-51cd-b2cf-4201d93a75a3_78a3e46e-5fb9-4dd3-900b-17ba7f867e2d.jpg?v=1698568536&width=1445)