Oh, oobee doo, lets look at creatures who wanna be like you
Deathbellow War Cry Tooth and Nail is not a fair card
Stealing a card might not 1 Counterspell YoU wAnT tO cAsT yOuR cOmMaNdEr
Creatures (20) Emrakul, the Aeons Torn x4 Oracle of Mul Daya Overgrown Battlement x4 Primeval Titan x4 Sakura-Tribe Elder Terastodon Ulamog, the Infinite Gyre Wall of Roots x4 Instants (7) Beast Within x3 Through the Breach x4 Sorceries (4) Artifacts (4) Gruul Signet x4 Lands (25) Cloudpost x4 Dryad Arbor Eye of Ugin Forest x3 Glimmerpost x4 Grove of the Burnwillows x4 Misty Rainforest x2 Mountain Stomping Ground Vesuva x4 Sideboard (15) Brooding Saurian Chalice of the Void x3 Dismember x2 Firespout x3 Punishing Fire x3 Qasali Pridemage Seal of Primordium x2 While Cloudpost is banned in Modern and Pauper due to its incredible mana production, you can still play 12-Post variants in Legacy, like with this list that finished top 8 during a recent Legacy preliminary on MTGO
They haven't been used too often, usually appearing as "one-off" mechanics in most sets
Be it a reanimator deck that needs self-mill, a storm deck, or a Splinter Twin + Pestermite combo deck, blue is usually involved somehow