Skullbriar, the Walking Grave

Commander is where Skullbriar, the Walking Grave lives — the 99-card singleton format gives it access to the full suite of proliferate effects, counter doublers, and voltron equipment that turns a persistent 2/2 into a one-shot threat. In Legacy and Vintage it's technically legal but practically invisible; a two-mana 2/2 with no immediate board impact can't compete with the raw speed of those formats, and the counter-persistence mechanic has no meaningful payoff in a game that often ends by turn three. Oathbreaker is the one non-Commander context where Skullbriar could theoretically slot in as a signature spell target or secondary threat, though the format's lower card counts thin out the support package it needs.