17 cards where the card types include “ox” and (the card is available on Paper) and the toughness <= 5

Arc Runner (Magic 2011 #123)
Bartered Cow (Throne of Eldraine #6)
Charging Cinderhorn (Commander 2016 #16)
Earth-Origin Yak (Global Series Jiang Yanggu & Mu Yanling #9)
Goldenhide Ox (Journey into Nyx #125)
Holy Cow (Outlaws of Thunder Junction #16)
Inquisitor's Ox (Shadows over Innistrad #24)
Ironhoof Ox (Portal Second Age #130)
Longhorn Firebeast (Torment #103)
Makindi Ox (Zendikar Rising #25)
Ox of Agonas (Neon Dynasty Commander #108)
Pillarfield Ox (Conspiracy #76)
Purphoros's Emissary (Double Masters 2022 #121)
Raging Bull (Legends #163)
Wild Ox (Starter 1999 #151)
Yoked Ox (Core Set 2020 #41)
Zodiac Ox (Portal Three Kingdoms #161)

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