Terrian is a mono-green stompy/counters engine: cast him as a built-in beater that enters loaded with +1/+1 counters, then attack to dig and cheat creatures into play off the top of your library while snowballing his size. Ramp hard early, deploy Terrian by turn 4-5, and use his attack trigger to free-cast fatties and accumulate counters until you swing for lethal or alpha-strike with a finisher.
Built-in card advantage and value every combat without needing extra cards
Cheats expensive creatures into play, dodging their mana costs
Synergizes with both ramp and +1/+1 counter doublers for explosive growth
Mono-green gives access to the best ramp and the cleanest mana base in the format
Self-recurring threat density makes the deck resilient to single removal spells
Mono-green has poor interaction with the stack and almost no spot removal for noncreatures
Relies on attacking, so it's slow against go-wide aggro or fast combo
Vulnerable to board wipes and edicts that strand its counter investment
Flying and evasive threats can race under the radar while you build a board
Removing or chump-blocking Terrian shuts off the value engine
Legendary Creature — Dinosaur Ooze
