So not only does this card negate their attack, it can also destroy your opponents monsters and do damage to their life points if the monster attacking was strong enough to do so
P/T Number 105 Language English Legal Formats Commander, Legacy, Modern, Pauper, Vintage Not Legal Formats Alchemy, Brawl, Competitive Brawl, Historic, Pioneer, Standard, Timeless Rulings (7/26/2024) Because damage remains marked on a creature until the damage is removed as the turn ends, nonlethal damage dealt to one Relentless Rats may become lethal if another Relentless Rats leaves the battlefield during that turn
On this particular Legendary Pikachu reverse holo, the holofoil is bright and shiny, making it a solid stand out
And you can have a 3/3 on turn 3 with proliferate tricks, but I'd prefer the ramping instead