Yoshimaru, Ever Faithful is a mythic Legendary Creature — Dog card from Secret Lair Drop (SLD), collector number 2463. Current market price: $7.92 (foil $8.51), TCGplayer market prices via Scryfall.
Whenever another legendary permanent you control enters, put a +1/+1 counter on Yoshimaru. Partner (You can have two commanders if both have partner.)