Correct
And to the person who used the D&D reference yes is the first game to reference tiamat as a 5 headed dragon. and was copyrighted at that time. however in 1982 through 1990 there was an open gaming act that tsr enacted to get more planes or modules for d&D there for any likeness even to mythological deities that d&d had copyrighted there revised likeness too could be used in any game without repercussions.
and unfortunately likenesses of deities and mythological figures can be copyrighted. As long as a specific likeness is given to them ie tiamet five headed dragon.
Just so long as the specific likeness is altered from the historical likeness.

