It's become commonplace for green to offer a 2-drop that gives you mana of any color
Box Toppers There are region-specific Box Topper cards in Streets of New Capenna

Advanced Search Sets Random Syntax Abbey Gargoyles Absolute Virtue Akki Lavarunner Akroma, Angel of Fury Akroma, Angel of Wrath Alseid of Life's Bounty Angelic Curator Animar, Soul of Elements Anurid Scavenger Apostle of Purifying Light Archon of Absolution Argentum Masticore Armored Guardian Auriok Champion Aven Liberator Aven Smokeweaver Azorius First-Wing Bamboozling Beeble Baneslayer Angel Basri's Lieutenant Beasts of Bogardan Beloved Chaplain Benevolent Bodyguard Black Knight Blightbeetle Bloated Toad Blood Baron of Vizkopa Blood Knight Bog Elemental Burrenton Forge-Tender Cartel Aristocrat Cemetery Gate Cephalid Snitch Cerulean Drake Cerulean Wyvern Chameleon Colossus Cho-Arrim Legate Cliffside Rescuer Coast Watcher Commander Eesha Council Guardian Crimson Acolyte Crusading Knight Crypt Angel Cybernetica Datasmith Darkwatch Elves Death Speakers Death-Mask Duplicant Defender of Chaos Defender of Law Devoted Caretaker Devout Lightcaster Diregraf Escort Disciple of Grace Disciple of Law Disciple of Malice Dragon Hunter Dragonstalker Dross Harvester Dunerider Outlaw Duskrider Falcon Duskrider Peregrine Eight-and-a-Half-Tails Elite Inquisitor Empty-Shrine Kannushi Emrakul, the Aeons Torn Emrakul, the Promised End Emrakul, the World Anew Enemy of the Guildpact Eon Frolicker Escaped Shapeshifter Etched Champion

But theyre still scarce enough on the secondary market that only two Near Mint copies remain on the Marketplace after the buyout
Enjoy going in response to someones uncounterable Banefire that was hoping to shoot you down for lethal
It tends to value highly in any set it appears in, but none are as rare as EX Deoxys' Rayquaza Gold Star, which only has 56 verified PSA 10 quality cards in circulation, putting it on par with the famous Holo Base Set Shadowless Charizard