If a creature's power is less than 0 when it's doubled, instead that creature gets -X/-0, where X is how much less than 0 its power is
The power of the blocking creature and that of Shrill Howler are compared only at the moment that blockers are chosen
From the trailer and what The Pokemon Company has shared so far, heres every card confirmed to be included in the upcoming Shining Revelry booster pack: Shiny Cards Charizard EX Lucario EX Pachirisu Wiglett Varoom Paldean Cards Iono Sprigatito Tatsugiri Other New Cards Pinsir Red In addition to the Shiny variants, it looks like the Shining Revelry packs will include standard versions of Charizard EX and Lucario EX, as well
The card has pretty significant wear and chipping shown on the backside
You can even have Marton be an honorary Goblin lord, since there are a ton of Goblin cards that make multiple Goblin tokens, like Siege-Gang Commander and Beetleback Chief
This four-black mana 5/5 creature with trample might not seem that impressive, but its ability makes it almost impossible to block