Just two in the X, which is 6 mana total, would be a 2d6 large monster around 7/7 on average, and it gets bigger from there
Siege-Gang Commander and Sling-Gang Lieutenant - Siege-Gang Commander has been a staple since it was first printed in Scourge
A sub-theme for Otters, however, is the ability to copy spells, which this Otter lord does beautifully

Gallery and List of Affinity Cards Affinity for Artifacts Assert Authority Blinkmoth Infusion Broodstar Chiss-Goria, Forge Tyrant Chromescale Drake Demonic Junker Don & Raph, Hard Science Emry, Lurker of the Loch Ethersworn Sphinx Frogmite Frogmyr Enforcer Furnace Dragon Furnace Hellkite Gearseeker Serpent Imskir Iron-Eater Into Thin Air Krang, Master Mind Lens Flare Memory Guardian Mycosynth Golem Myr Enforcer Plated Onslaught Quicksilver Behemoth Qumulox Reality Heist Refurbished Familiar Saheeli, the Gifted Sami, Wildcat Captain Scale of Chiss-Goria Slag Strider Sojourner's Companion Somber Hoverguard Steelfin Whale Tezzeret, Master of the Bridge Thoughtcast Thought Monitor Tooth of Chiss-Goria Utrom Monitor Valkyrie Aerial Unit Voyage Home Affinity for Lands Affinity for Equipment One-Off Affinity Abilities Allies at Last Banish to Another Universe Banquet Guests Bartz and Boko Hellspur Brute Junk Winder Pearl-Ear, Imperial Advisor Salt Road Packbeast Sapling Nursery The Dalek Emperor Thrumming Hivepool Tomik, Wielder of Law Travel the Overworld Urza, Chief Artificer Note that there's also Omniclown Colossus with affinity for clowns, but it's an Unfinity card so it's up to you if you want to count it or now

Your opponents have your life points down to 0 by turn 3 with ease