Your search for "Magnigoth Sentry 556" revealed the following:
Magnigoth Sentry (FDN) from Foundations, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: Dave Kendall Card Text:Reach (This creature can block creatures with flying.)
Magnigoth Sentry (DMU) from Dominaria United, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: Dave Kendall Card Text:Reach
Magnigoth Sentry - Art Series (Gold-Stamped Signature) (ADMU) from Dominaria United Art Series, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: Dave Kendall