K-9, Mark I
Legendary Artifact Creature — Robot Dog{U}1/1
Negative — As long as K-9 is untapped, other legendary creatures you control have ward {1}. Affirmative — {1}{U}, {T}: Target legendary creature can't be blocked this turn. Doctor's companion (You can have two commanders if the other is the Doctor.)
Colour identity Blue · Negative, Affirmative, Doctor's companion · Commander page
In short
K-9, Mark I has 6 listed printings; the most valuable is the Showcase · Surge Foil printing from WHO at US$48.86 on TCGplayer's market price. Prices below are the cheapest in-stock listing in the United States.
Every K-9, Mark I printing
Showcase · Surge Foil
K-9, Mark I
WHO · 1128
TCGplayer market
US$48.86
Extended Art · Surge Foil
K-9, Mark I
WHO · 953
TCGplayer market
US$7.37
Surge Foil
K-9, Mark I
WHO · 652
TCGplayer market
US$6.30
Showcase
K-9, Mark I
WHO · 537
Price not tracked
Extended Art
K-9, Mark I
WHO · 362
TCGplayer market
US$4.27
K-9, Mark I
WHO · 47
TCGplayer market
US$3.14