Note: Most PowerPC Macs cannot natively boot from USB. However, OpenFirmware tricks exist for later G4/G5 models. This is advanced and not recommended for beginners.
Before attempting an installation, verify your vintage Mac meets these minimum specs: : PowerPC G3, G4, or G5 (minimum 233 MHz). mac os x 10.3 panther dmg download
If you are searching for a DMG of Panther, you will likely encounter two major obstacles: obsolescence and authenticity. Note: Most PowerPC Macs cannot natively boot from USB
While official downloads are unavailable, preservation sites that host abandonware (where copyright is ignored or claimed as fair use for historical/educational purposes) sometimes provide Panther images. Examples include: mac os x 10.3 panther dmg download