In my opinion, these are licensed cards with Pokemon printed on them, but not Pokemon cards. Pokemon cards are made by The Pokemon Company / The Pokemon Company International (TPC/TPCi) for official play
However, there are many shapeshifter creatures out there that dont have the changeling mechanic

Abolisher of Bloodlines Abundant Maw All Is Dust Angelic Aberration Anticausal Vestige Artisan of Kozilek Aurora of Emrakul Azlask, the Swelling Scourge Bane of Bala Ged Barrage Tyrant Basking Broodscale Bearer of Silence Benthic Anomaly Benthic Infiltrator Birthing Hulk Bismuth Mindrender Blight Herder Blinding Drone Blisterpod Breaker of Armies Breaker of Creation Brisela, Voice of Nightmares Brood Butcher Brood Monitor Broodwarden Catacomb Sifter Chittering Dispatcher Chittering Host Conduit of Emrakul Conduit of Ruin Corrupted Shapeshifter Cryptic Cruiser Culling Drone Cultivator Drone Deathless Behemoth Deceiver of Form Decimator of the Provinces Deepfathom Skulker Depth Defiler Desolation Twin Devourer of Destiny Dimensional Infiltrator Distended Mindbender Dominator Drone Dread Defiler Dread Drone Dronepack Kindred Drowner of Hope Drowner of Truth Drownyard Behemoth Drownyard Lurker Dust Stalker Echoes of Eternity Elder Deep-Fiend Eldrazi Aggressor Eldrazi Conscription Eldrazi Devastator Eldrazi Displacer Eldrazi Linebreaker Eldrazi Mimic Eldrazi Obligator Eldrazi Ravager Eldrazi Repurposer Eldrazi Skyspawner Eldritch Immunity Emrakul's Hatcher Emrakul's Messenger Emrakul, the Aeons Torn Emrakul, the Promised End Emrakul, the World Anew Endbringer Endless One

Youll find that there are groups of people that go back and really take a hard look at old formats that are not yet solved and try to come up with a new thing
It's simple, synergistic, and far more powerful than opponents expect when they see a Bear tribal deck across the table
Mentor of the Meek : Draws you a card whenever a low-power creature enters the battlefield under your control