Including Tawnos's Coffin, Cold Storage, and other colorless blink is a good way to go in this deck
Spitting DilophosaurusSpitting Dilophosaurus would be a fantastic addition to either of those two, being able to give a -1/-1 counter when it enters, then repeat that every time it attacks is just good value
Each Lost Caverns of Ixalan Commander Deck includes 1deck of 100 Magic cards (2 Traditional Foil Legendary cards, 98 nonfoil cards), a 2-card Collector Booster Sample Pack (contains 2 alt-border cards, with 1 Traditional Foil or nonfoil card of rarity Rare or higher and 1 Traditional Foil Uncommon card), 1 foil-etched Display Commander (a thick cardstock copy of the commander card with foil etched into the cards border and art), 10 double-sided tokens, 1 deck box (can hold 100 sleeved cards), 1 Life Wheel, 1 strategy insert, and 1 reference card.
Commander games are often decided by who ramps fastest, and this card wins that race
Whenever Perrie attacks, target creature you control gains trample and gets +X/+X until end of turn, where X is the number of different kinds of counters among permanents you control