I'm quite surprised about the absence of a thread about the mighty Zanthor!
Zanthor appeared in the episode "The Golden Disks Of Knowledge" and I know that he isn't an essential but he can be a Travelling Figure.
Check the pictures from the episode:
With the Golden Disks Of Knowledge:
As Zodac helper:
A raw mockup:
And finally the list of the parts that we need:
New: head, helmeted head, armor and golden disks (realized in the same fashion of the piece of the Dark Star that comes with Strobo)
TRU Zodac: enforcer armor, legs, arms and loincloth
and finally a regular human torso