Speaking of Hollywood theology, Ghostbusters didn’t get it quite right.
(Interestingly, three out of those four characters have STEM PhDs, as I recall…)
Yes, the reversal of the natural order can be a sign of the end times, especially if that reversal, and the violation of natural law, is being done happily and willfully by mankind.
(And extra especially if man is calling this reversal a reflection of Christ’s teaching and God’s will. That’s why the original readers of the novel, and some Hammer producers, tended to get it right: Dr. Frankenstein is the real “monster,” not his creature.)
However, we are also told (and this is a poetic metaphor, not literal, you certain Protestants out there) that “the wolf” — no, not “the lion” — “will lie down with the lamb” when Christ returns. (Or showed up in the first place as this Protestant guy posits.)
So it is hard to say whether or not “dogs and cats, living together” is a good sign or a bad sign.