19 cards where the power >= 7 and the toughness >= 7 and the rarity is equal to common

A-Capenna Express (Streets of New Capenna #A-139)
Ancient Brontodon (Ixalan #175)
Cavern Stomper (The Lost Caverns of Ixalan #177)
Depth Charge Colossus (The Brothers' War #78)
Duskdale Wurm (Iconic Masters #161)
Eldrazi Devastator (Battle for Zendikar #7)
Goliath Sphinx (Commander Masters #99)
Greater Sandwurm (Ikoria: Lair of Behemoths #157)
Grizzled Outcasts // Krallenhorde Wantons (Innistrad #185)
Grizzled Outcasts // Krallenhorde Wantons (Innistrad #185)
Hand of Emrakul (Rise of the Eldrazi #5)
Maelstrom Colossus (Commander Legends #322)
Marut (Commander Legends: Battle for Baldur's Gate #322)
Morkrut Necropod (Shadows over Innistrad Remastered #125)
Ruin Processor (Battle for Zendikar #12)
Rust Goliath (The Brothers' War #204)
Thundersteel Colossus (Kamigawa: Neon Dynasty #261)
Ulamog's Crusher (Commander Masters #6)
Vorstclaw (Core Set 2020 #201)
Walker of the Grove (Ultimate Masters #191)

Though this query has ended, its relics still slumber in New Argive.