The word was Vorherrscher, but that’s more a general term for the offspring of two different types of Wesen, not something that’s specific to a Blutbad and Fuchsbau.
According to Rosalee and Monroe, the offspring of two different types of Wesen will have the traits of the dominant Wesen species. It’s not clear what is meant by “dominant” in this case, but either way the implication is that their kids will carry the genes of both types but only display the traits (woge and abilities) of one parent.
I hope we get the Grimm spin-off too! And I hope we get to see those lil babies all grown up and badass.