Disclaimer: asking about revelation is going to generate a flood of answers. There is no profit in disputing interpretations of Revelation.
"antichrist" doesn't appear in Revelation, it appears only in John's epistles.
In 1 John 2.18-22, the 'antichrist' is used as a reference to false Christians who "went out from us", e.g. abandoned the churches.
Here, the antichrist is defined as someone that denies that Jesus is messiah: "Who is a liar but he that denieth that Jesus is the Christ? He is antichrist, that denieth the Father and the Son."
In 1 John 4.3, there is a reference to the "spirit" of antichrist, which is to deny that Jesus is come in the flesh. This could be a reference to denying the bodily incarnation, but also as denying the incarnation of Christ in each believer's flesh, as those who do not believe that Jesus Christ is "in you" are called "reprobates" in Paul's work.
In 2 John 7, again the definition of "denying that Jesus is come in the flesh" is used but this time not as a spirit, but as an antichrist, again with the idea that there are many antichrists.
Thus in John, an antichrist is a category of unbelievers who share some of the similiarities of believers but refuse to believe that Jesus is the messiah or, equivalently, do not believe that Jesus came in the flesh (in Bethlehem) or that Jesus is not born in believers, so they are not born again.
As per Augustine:
Whom has he called antichrists? He goes on and expounds. “Whereby we
know that it is the last hour,” By what? Because “many antichrists are
come. They went out from us;” see the antichrists! “They went out from
us:” therefore we bewail the loss. Hear the consolation. “But they
were not of us.” All heretics, all schismatics went out from us, that
is, they go out from the Church; but they would not go out, if they
were of us. Therefore, before they went out they were not of us. If
before they went out they were not of us. many are within, are not
gone out, but yet are antichrists. We dare to say this: and why, but
that each one while he is within may not be an antichrist? For he is
about to describe and mark the antichrists, and we shall see them now.
And each person ought to question his own conscience, whether he be an
antichrist. For antichrist in our tongue means, contrary to Christ.
Not, as some take it, that antichrist is to be so called because he is
to come ante Christum, before Christ, i.e. Christ to come after him:
it does not mean this, neither is it thus written, but Antichristus,
i.e. contrary to Christ. Now who is contrary to Christ ye already
perceive from the apostle’s own exposition, and understand that none
can go out but antichrists; whereas those who are not contrary to
Christ, can in no wise go out. For he that is not contrary to Christ
holds fast in His body, and is counted therewith as a member. The
members are never contrary one to another.
Augustine of Hippo. (1888). Ten Homilies on the First Epistle of John. In P. Schaff (Ed.), H. Browne & J. H. Myers (Trans.), St. Augustin: Homilies on the Gospel of John, Homilies on the First Epistle of John, Soliloquies (Vol. 7, pp. 476–477). New York: Christian Literature Company.
Whether that concept appears in the book of Revelation depends very much on how you interpret Revelation. But let's search for it.
Looking for antichrists in Revelation
The essence of the antichrist then is denying the messiah and thus it would be blasphemy.
In Revelation, that would be the men who are being punished with plagues (Rev 16.21, Rev 16.11, Rev 16.9) who blaspheme God, or the beast that comes out of the sea:
And there was given unto him a mouth speaking great things and
blasphemies; and power was given unto him to continue forty and two
months. And he opened his mouth in blasphemy against God, to blaspheme
his name, and his tabernacle, and them that dwell in heaven.
So both of these could be considered antichrists in Revelation. Really anyone not born again who is actively denying Christ is an antichrist. But the nice thing about the beast with seven heads is the passage
"blasphemy against God, to blaspheme his name, and his tabernacle, and them that dwell in heaven."
- Blaspheming the name of God would be denying his character and specifically the name of Christ.
- Blaspheming his tabernacle would be a good match for denying the incarnation or indwelling of Jesus
- Blaspheming them that dwell in heaven would correspond to denying that believers are seated with God in the heavenlies, which is also a type of denial of those who are born from above.
So that would be a reasonable correspondence. But the second beast, e.g. the beast out of the land, is worshipping the image of the beast out of the sea, so if the first beast meets the criteria of antichrist which is denial, then the second beast must also meet it, as would anyone who worships the image of the beast from the sea.
Thus the classification of "antichrist" would spread to all who dwell on the earth, since all of these worship the beast. Only those portrayed as dwelling in heaven (e.g. Christians as per Eph 2.6) would not be counted as antichrists according to the definition of John.
And of course the beast out of the sea worships with the voice of the dragon, so we have a hierarchy of blasphemy:
beast out of the sea
beast from the land
all men who "dwell on earth"
All of the above would be "anti-Christs", whose those on one layer being controlled by the layer above them.
From then, we can look at jewish traditions of what meant to be called a "beast", or "brute beast", and symbolism of the dragon, etc. That's a whole book, but some brief summaries:
Second Temple Apocalyptic literature
The second temple apocalyptic literature associated two "beasts" at the end of the world, Leviathan (which came from the sea) and Behemoth (which came from the land, and is a majestic plural of "beast") often portrayed as mates or brothers. Leviathan was assumed to be the stronger of these and in some sense "powered" Behemoth. Both would be conquered and eaten during the feast of tabernacles, where the scales of Leviathan would decorate the booths and the meat of behemoth would be eaten by the victorious saints at the consummation of the age. E.g. 2 Baruch 29.3-4. 4 Ezra 60.50-51. See also Targum Jonathan
God created the great sea monsters, Leviathan and his mate, that are
designated for the day of consolation
Or in the Babylonian Talmud, we have
As long as Leviathan is alive, Behemoth is also safe
Traditional old testament literature
a beast is someone who arrogantly denies God and follows his senses (think Nebuchednezzar turned into an ox Dan 4.25). Psalm 49.
The "essence" of this arrogant beastly nature is distilled into the Behemoth (a majestic plural of Beast). Job 48.
Leviathan, along with all the other sea monsters in the bible, is a symbol of the world system, both of Egypt and Babylon. Leviathan will be defeated on the day of the Lord (Is 27.1, Ps 74.13-14). But we also see that he was defeated at passover, e.g. during the exodus, when God cut the monster in two (Is 51.9-11). Revelation portrays Leviathan as having a mortal headwound. For us, that would be a victory on the cross. Yet the little beast, the one from the earth, temporarily resurrects this beast and worships it.
Interestingly, we have this notion of Leviathan going back to ancient times. E.g. in the Anchor Yale Bible's commentary on Job:
A Mesopotamian seal cylinder from Tell Asmar depicts a seven-headed
dragon in the process of being subdued by two divine heroes. One
attacks from the rear while the other battles the monster head on.
Four of the dragon’s heads are drooping, but the three upper ones are
still erect with forked tongues protruding. The creature has six long
tongues of flame rising along its back. The cylinder dates from the
early Akkadian period, but certainly represents a prototype of the
seven-headed serpentine monster Leviathan (cf. H. Frankfort,
Stratified Cylinder Seals from the Diyala Region, Pl. 45, No. 478, and
J. B. Pritchard, ANEP, 691).
So one interpretation the beast from the land would represent arrogant, beastly, man as an individual who is mated with and subservient to the beast from the sea which represents both the dragon and the "spirit of the world". This would be why an icon must be made to worship the beast of the sea, as this beast cannot be interacted with directly except within the heart of the beastly men and except via a specific representation appropriate for each age/culture/value system.
Then all men who dwell on the earth, that is who do not dwell in the heavenlies, are controlled by this beastly nature and made to worship the one with 7 heads, that is, they can't help but think of earthly things and deny that Jesus is the Christ or that Jesus is come in the flesh.
In this intepretation, in this image of the two beasts, we see Revelation as providing a spiritual elaboration on the phenomena of antichrists.
 Cathcart, K., Maher, M., & McNamara, M. (Eds.). (1992). The Aramaic BibleB: Targum Pseudo-Jonathan: Genesis. (M. Maher, Trans.) (Vol. 1, Ge 1:21). Collegeville, MN: The Liturgical Press.
 b. Baba Batra 5:1a, IV.24.A–F