Chishiro, the Shattered Blade is a mythic Legendary Creature — Snake Samurai card from Magic Online Promos (PRM), collector number 98087.
Whenever an Aura or Equipment you control enters, create a 2/2 red Spirit creature token with menace. At the beginning of your end step, put a +1/+1 counter on each modified creature you control. (Equipment, Auras you control, and counters are modifications.)