Theres also a few triggered abilities that further double-counters, like Byrke, Long Ear of the Law and Fractal Harness
Auntie Ool, Cursewretch Auntie Ool, Cursewretch punishes enemies with life loss when their creatures shrink while rewarding you with cards whenever your own creatures pick up -1/-1 counters
This means that if you have no cards on your Bench your Active Spot Pokmon is going to get hit with 150 DMG (170 DMG with Red if your Active is an EX)
The card, Radioactive Spider, will have a single unique version with real radiation
the Pokmon TCG database is a good place to start for this, but you might also find help from a friendly collector, dealer or via a collectors' group on social media
It's best combined with cards that create token creatures when you cast spells, as it'll give you a large number of creatures to attack with