Linux Equivalent of Windows Ctrl to show Mouse Pointer
Open Terminal and run the following command
gsettings set org.gnome.settings-daemon.peripherals.mouse locate-pointer true
Now if you press ctrl the pointer should be highlighted.
It is possible to find this option in the GNOME Tweaks. Just go to 'Keyboard & Mouse' -> 'Pointer Location' and turn it on/off.
In 20.04, this is a slightly different location now for gsettings
to work with.
In 20.04, this is the org.gnome.desktop.interface locate-pointer
object. So:
gsettings set org.gnome.desktop.interface locate-pointer true