17 cards where the text includes “defender” and the card types include “creature” and the color identity ≤ GUW and the toughness > 5 and it’s legal in Commander and the mana value < 4

Shield Sphere (Masters Edition #166)
Fortified Rampart (Battle for Zendikar #27)
Ludevic's Test Subject // Ludevic's Abomination (Innistrad #64)
Ludevic's Test Subject // Ludevic's Abomination (Innistrad #64)
Thing in the Ice // Awoken Horror (Shadows over Innistrad #92)
Thing in the Ice // Awoken Horror (Shadows over Innistrad #92)
Ulvenwald Captive // Ulvenwald Abomination (Eldritch Moon #175)
Ulvenwald Captive // Ulvenwald Abomination (Eldritch Moon #175)
Wall of Junk (Dominaria Remastered #240)
Wall of Shards (Coldsnap #23)
Wall of Tanglecord (Scars of Mirrodin #222)
Glacial Wall (Eternal Masters #53)
Guardians of Meletis (Magic Origins #228)
Hover Barrier (Return to Ravnica #40)
Quicksilver Wall (Prophecy #41)
Wall of Denial (Commander Masters #939)
Wall of Frost (Modern Masters 2017 #56)
Wall of Ice (Fourth Edition #283)
Wall of Nets (Exodus #24)
Wall of Resurgence (Oath of the Gatewatch #39)

In the blink of an eye, they strode from deep snow to the end of this search.