Omnath, Locus of the Roil {1}{G}{U}{R}
Legendary Creature — Elemental
Identity
Temur
EDHREC rank
#3,564
Cheapest printing
US$0.41
TCGplayer
Printings
4
When Omnath enters, it deals damage to any target equal to the number of Elementals you control.
Landfall — Whenever a land you control enters, put a +1/+1 counter on target Elemental you control. If you control eight or more lands, draw a card.
Keywords: landfall
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.