Red / Green: Expend 4 ( Raccoons ) Expend is fundamentally an aggressive mechanic that encourages you to spend mana, and Wandertale Mentor encapsulates that idea perfectly with a two drop that both taps for mana (allowing you to Expend 4 on turn 3) while also growing bigger to become a scary threat in the late game

Akrasan Squire Angelic Benediction Ardent Plea Aven Squire Bant Battlegrace Angel Cathedral of War Court Archers Dauntless Escort Avatar Dawnray Archer Duskmantle Prowler Duty-Bound Dead Emissary of Soulfire Ethercaste Knight Exalted Angel Exalted Dragon Exalted Flamer of Tzeentch Finest Hour First Sliver's Chosen Frontline Sage Giltspire Avenger Goblin Champion Guardians of Akrasa Ignoble Hierarch Knight of Glory Knight of Infamy Merchant of Truth Nefarox, Overlord of Grixis Noble Hierarch Order of Sacred Dusk Outrider of Jhess Qasali Pridemage Rafiq of the Many Rammas Echor, Ancient Shield Rhox Bodyguard Rhox Charger Servant of Nefarox Sighted-Caste Sorcerer Sigiled Behemoth Sigiled Paladin Sovereigns of Lost Alara Sublime Archangel The Book of Exalted Deeds Urza's Dark Cannonball Waveskimmer Aven Zarda, the Power Princess
Here, Dragons is a clear winner, just because it has so many reprinted commanders
What you see in the preview is what gets printed
9 Sachi, Daughter Of Seshiro An interesting dual-type commander, Sachi provides support to both Snakes and Shamans, though not necessarily in equal measure
Nobody would ever be willing to drop a thousand dollars on a card that WotC could turn around and put in a set tomorrow