PPC emulator to run Tiger
It is now possible to emulate PowerPC for Mac OS 9.2.2 through 10.5 via QEMU: https://wiki.qemu.org/Documentation/GuestOperatingSystems/MacOS10.4 and https://wiki.qemu.org/Documentation/Platforms/PowerPC.

You'll need to install homebrew, a package manager for Mac OS X/OS X/macOS. Then run brew install qemu (which already contains the PowerPC part).

To create the a hard disk image, run 

qemu-img create -f qcow2 example.img 100M


replacing 


example.img with the path you want to store your disk image in
100M with the size you want (at least 3.0GB to install Tiger according to Apple, probably about 10GB to be safe).


You could also use a sparse (bundle) disk image with QEMU (you'll then be able to natively mount it within the host) but that requires a bit of setup and a script.

You can run then Tiger with

qemu-system-ppc -L pc-bios -boot d -M mac99 -m 512 -hda example.img \
    -cdrom &lt;iso file of installation media&gt; \
    -netdev user,id=mynet0 -device sungem,netdev=mynet0 `


where  is the ISO of a Tiger install disk (you could also use the disk directly as well as dmg images using the same method for a sparsebundle)