Triskel - KDE live image

There isn't one anymore, unless someone from the community wants to step up and take over maintenance. Otherwise, you install Trisquel normally and then install the Triskel package. If you don't want to go through the process of first installing GNOME and such, it is also possible to use the netinstall image instead which sets up a very basic system and then install the Triskqel package from there.

You probably want "triskel-recommended" too:
$ sudo apt-get install triskel triskel-recommended