Joel 2

"Blow the trumpet in Zion, and sound an alarm in My holy mountain! Let all the inhabitants of the land tremble; for the day of the Lord is coming, for it is at hand: a day of darkness and gloominess, a day of clouds and thick darkness, like the morning clouds spread over the mountains. A people come, great and strong, the like of whom has never been; nor will there ever be any such after them, even for many successive generations.  A fire devours before them, and behind them a flame burns; the land is like the Garden of Eden before them, and behind them a desolate wilderness; surely nothing shall escape them.  Their appearance is like the appearance of horses; and like swift steeds, so they run...The Lord gives voice before His army, for His camp is very great; for strong is the One who executes His word.
For the day of the Lord is great and very terrible; who can endure it?" vv.1-4,11
Read chapter 2.
Centaurs are in the Bible!  It appears that during the kingdom of the antichrist there are supernatural beings like this people with the appearance of horses (v.4).  This chapter has a lot going on it seems like, both future happenings and the then present happenings with the nation of Israel.  A big question to ask here is what is the Day of the Lord?  From the descriptions in this chapter alone, we can see it's not all a peaceful, heaven time.  It appears to be a time when Christ is executing judgment towards the end of the time of the tribulation.  Here we see the inhabitance in Zion tremble, which seems that the tribulation is only or mainly happening in Jerusalem.  It's a day of darkness and gloominess.  A great and strong army devoting the land and people.  Yet the best is that with just Christ's voice the army against Him and His people is taken out (v.11).  The Day of the Lord is not something the faithful should fear in that time, only the unfaithful who openly rebel against the Lord during that time of tribulation, time of great testing.  It is a "great and awesome day of the LORD" (v. 31).  Begin a list of characteristics you see that define this time of the Day of the Lord as you continue to read scripture?