Proliferate is a keyword action that lets you choose any number of players or permanents and put an extra counter on them for each type of counter already there
Here's the full card list for the Wugtrio ex starter deck: Tentacool x2 Tentacruel Buizel x2 Floatzel Wiglett x2 Wugtrio ex Tatsugiri Dondozo Rattata x2 Raticate X Speed Pok Ball x2 Professor's Research x2 Iono If you're looking for fat to trim in this deck, you can easily cut the Rattata, Tentacool, and Buizel lines, which are largely just taking up space
x1] [When Attacking] Rest up to 1 of your opponent's Characters with a cost equal to or less than the total of your and your opponent's Life cards
After that comes Dragapult/Dusknoir, then Raging Bolt/Ogerpon, and then two Charizard/Pidgeot decks
They have the Multiverse at their oily fingertips, they have an army the likes of which no plane has ever seen, and they have devastated and compleated the Planeswalkers who sought to stop them