Tromell, Seymour's Butler {2}{G}
Legendary Creature — Elf Advisor
GreenCommander: legal
Identity
Green
EDHREC rank
#3,951
Cheapest printing
US$0.29
TCGplayer
Printings
3
Each other nontoken creature you control enters with an additional +1/+1 counter on it.
{1}, {T}: Proliferate X times, where X is the number of nontoken creatures you control that entered this turn. (To proliferate, choose any number of permanents and/or players, then give each another counter of each kind already there.)
Keywords: proliferate
Every printing
highest TCGplayer market first; a card with only a thin single listing shows its low
In short
A Commander deck is a commander and 99 other cards, one copy of each (except basic lands), all inside the commander's colour identity. Paste a full list into the deck price calculator to price it and check it against the format.