43 cards where the card types include “cat” and (the card is available on Paper) and it’s legal in Future Standard

Ajani's Pridemate (Foundations #135)
Arahbo, the First Fang (Foundations #2)
Bola Slinger (March of the Machine #8)
Bounding Felidar (Outlaws of Thunder Junction #5)
Chrome Prowler (Phyrexia: All Will Be One #45)
Dawnwing Marshal (Foundations #570)
Enduring Curiosity (Duskmourn: House of Horror #51)
Envoy of Okinec Ahau (The Lost Caverns of Ixalan #11)
Felidar Cub (Foundations #573)
Felidar Savior (Foundations #12)
Forum Familiar (Murders at Karlov Manor #16)
Helpful Hunter (Foundations #16)
Ingenious Leonin (Foundations #495)
Ironpaw Aspirant (The Lost Caverns of Ixalan #18)
Jazal Goldmane (Commander Masters #32)
Kemba, Kha Enduring (Phyrexia: All Will Be One #19)
Kutzil, Malamet Exemplar (The Lost Caverns of Ixalan #232)
Kutzil's Flanker (The Lost Caverns of Ixalan #20)
Leonin Lightbringer (Phyrexia: All Will Be One #20)
Leonin Skyhunter (Duel Decks: Knights vs. Dragons #7)
Leonin Vanguard (Core Set 2019 #22)
Lionheart Glimmer (Duskmourn: House of Horror #19)
Malamet Brawler (The Lost Caverns of Ixalan #199)
Malamet Veteran (The Lost Caverns of Ixalan #201)
Malamet War Scribe (The Lost Caverns of Ixalan #21)
Nine-Lives Familiar (Foundations #66)
Nishoba Brawler (Dominaria United #174)
Prideful Parent (Foundations #21)
Progenitor Exarch (March of the Machine #32)
Regal Caracal (Foundations #579)
Roxanne, Starfall Savant (Outlaws of Thunder Junction #228)
Savannah Lions (Foundations #146)
Skyknight Squire (Foundations #23)
Soul of Windgrace (Dominaria United #220)
Sovereign Okinec Ahau (The Lost Caverns of Ixalan #240)
Streetwise Negotiator (March of the Machine #207)
Sunspine Lynx (Bloomburrow #155)
Topiary Panther (Murders at Karlov Manor #179)
Trained Arynx (Outlaws of Thunder Junction #36)
Warehouse Tabby (Wilds of Eldraine #117)
Wary Thespian (Foundations #235)
Ygra, Eater of All (Bloomburrow #241)
Zar Ojanen, Scion of Efrava (Dominaria United #227)

The message was clear to Sorin—time to search for something else.