I have considered the whole issue of PLANET X for many years. I have been most interested in the possibility that some large body might have passed through. Scientists now say there are at least 2-3 more undiscovered planets in our solar system. So, it is possible that one of these has a highly elliptical orbit - and it cannot be ruled out that it may also contain life, simple or complex.
The imposition of any large body upon our regional stability can cause greater disruptions than gravitational, and comet-orbit-alterations. According to (my/) ELECTRIC UNIVERSE THEORY, great electrical arcs, radiations and even nuclear eruptions, may be possible on any planets during the pass-by. Solar activity can also change dangerously. Because our planet has been experiencing some of these sorts of variations lately, including magnetic pole shift in-process, it must be considered that a body may be nearing our inner solar system presently. We do not know.
One thing science is now 98% sure of, presently, is something DID pass through our solar system, at about the same time of the TOBO SUPERVOLCANO eruption, and of a massive diminishment of our homo sapiens sapiens species' numbers. It has been found that a STAR passed through! Actually, two small stars.
Therefore, it can be said that the weirdo PLANET X theory has been valid. If this star was not in fact so-called "PLANET X", it does show that the possibility of some other large body passing through, recently, is a reasonable hypothesis.
Incidentally, along with ancient folk lore of such events, there continues lore of a great coastal civilisation existing on Earth up to around the same time, but which vanished as the oceans suddenly rose. (I have a theory about the sudden rise of the oceans, which I hope to get around to discussing one day).
Well, never dismiss ancient rumours, or stupid natives, or the wind, or the stars. They can't all be wrong. the universe is far more mysterious and magical and dangerous than we give it credit for, we snivelling little bankster-type primate-rats.
Alien star system buzzed the Sun - http://www.bbc.com/news/science-environment-31519875
Toba catastrophe theory - https://en.wikipedia.org/wiki/Toba_catastrophe_theory
Crazy man resurrected - https://en.wikipedia.org/wiki/Worlds_in_Collision