When viewing each of the abilities it is easy to assume that the card belongs in Zombie tribal, but taking a step back the card is independent and functions as its own enabler and payoff
(Players dealt combat damage by them also get a poison counter.) Corrupted At the beginning of your upkeep, if an opponent has three or more poison counters, choose a creature you control, then draw cards equal to its total toxic value
When that opponent loses, you win , meaning now you only have to take out one other player instead of all three opponents to win a game of Commander
Basically, take any other archetype you can think of, slap artifact onto its name, and you have a viable sub-archetype
As a silver-bordered card, Grimlock is not legal in officially-sanctioned events and formats but is fine for casual play, and as such gets a bit silly with its rules