19 cards where the text includes “changeling” and the card types include “creature” and the color identity ≤ BG and it’s legal in Commander

Bloodline Pretender (March of the Machine Commander #350)
Cairn Wanderer (Commander 2020 #130)
Chameleon Colossus (Forgotten Realms Commander #153)
Changeling Outcast (Outlaws of Thunder Junction Commander #128)
Changeling Titan (Lorwyn #200)
Game-Trail Changeling (Morningtide #123)
Ghostly Changeling (Modern Masters 2015 #83)
Gladewalker Ritualist (Kaldheim #392)
Graveshifter (March of the Machine Commander #251)
Guardian Gladewalker (Kaldheim #174)
Littjara Glade-Warden (Kaldheim #182)
Masked Vandal (Kaldheim #184)
Moonglove Changeling (Morningtide #67)
Realmwalker (The Lost Caverns of Ixalan Commander #250)
Skeletal Changeling (Lorwyn #140)
Universal Automaton (Modern Horizons #235)
Venomous Changeling (Modern Horizons #114)
Webweaver Changeling (Double Masters 2022 #164)
Woodland Changeling (Lorwyn #242)

This search is finished. Now the real work can begin.