It's a temporary mana maker, and I prefer permanent ones like land rampers in spell form like Cultivate, Rampant Growth or Explosive Vegetation or in dork form like Sakura-Tribe Elder, Wood Elves or Solem Simulacrum to ramp the harder to answer lands
It has great synergy with our Dragon Spirit Tokens created by Vrondiss, Rage of Ancients, as they are sacrificed when they deal damage, so they replace themselves with the help of Outpost Siege and Vrondiss
Now the value of the card appears to be clearly shrinking, as new copies of Umbreon ex are changing hands for under $3,000
68/130 Caterpie
Making heavy use of aura tokens (along with Food and the cant block clause on Rats) ensured players could always fuel Bargain and Celebration without giving them unlimited chump-blockers, which often invalidates the combat step in token-heavy Limited sets
Death Cloud Smallpox, but a bunch more times