It ressembles Totodile's long lost cousin, maybe it's a savage version of it, one that didn't evolved for centuries… Rusta's name comes from the french word "Rustre" which is a brutal, ill-manered individual as well as being a shorter, rearranged version of Kratarus' name.
Kratarus' name originate from the Krampus, Tartarus as in the name of the primitive god of Chaos and the Latin word for Barbarian / Barbaric (Barbarus). I wanted to convey a name of a "mythical" creature that is up to absolutely no good no matter what.
by MonsieurMidnight