Acridian

Echo {1}{G} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)

Flavor Text: The elves of Argoth were trained to ride these creatures, even when their mounts traveled upside-down.

Card Details:
Set: Urza’s Saga
Collector Number: 230
Artist: rk post