What is the Catholic understanding of Antichrist? Is there a good explanation describing how to identify the anti-Christ?
They say a lot of false prophets will rise up in the end times to preach the anti-Christ.

Is there a biblical explanation or does the Catholic Church had an official teaching about the anti-Christ?
The Antichrist is a single person, but anyone opposed to Christ can also be called an antichrist:
Sacræ Theologiæ Summa IVB on the Last Things, §264 &quot;The coming of the Antichrist&quot;, PDF pp. 462-463, says &quot;Antichrist&quot;

designates: a) broadly, the one who is Christ’s adversary, so that therefore there are many anti­christs; b) but by antonomasia, someone coming at the end of the world as a bitter enemy of Christ.

Fr. Hardon, S.J.'s Catholic Dictionary defines &quot;Antichrist&quot; as:

The chief of Christ's enemies. The New Testament specifically names him only in I John 2:18,

Little children, it is the last hour; and as you have heard that Antichrist cometh, even now there are become many Antichrists: whereby we know that it is the last hour.

2:22;

Who is a liar, but he who denieth that Jesus is the Christ? This is Antichrist, who denieth the Father, and the Son.

4:3,

And every spirit that dissolveth Jesus, is not of God: and this is Antichrist, of whom you have heard that he cometh, and he is now already in the world.

and II John [1:]7,

For many seducers are gone out into the world, who confess not that Jesus Christ is come in the flesh: this is a seducer and an antichrist.

where he is identified with unbelievers who deny the Incarnation. Over the centuries the Antichrist has been variously associated with historical persons, e.g., Caligula, Simon Magus, and Nero, or again with organized movements such as Arianism. The more common Catholic interpretation says that he is not merely symbolic or an embodiment of the anti-Christian. The Antichrist is a real person. (Etym. Greek antichristos, against Christ.)

The coming of Antichrist is one of the signs of Christ's second coming.
See also:

&quot;What is the Catholic interpretation of 2 Thessalonians 2:3&quot; (that Antichrist &quot;sitteth in the temple of God&quot;)?