As to beasts of Revelations: mark is an identifier. Identification for taxation and government control. Beast is laws of government.

Revelation 13:17, KJV: "And that no man might buy or sell, save he that had the mark, or the name of the beast, or the number of his name."

Capitalism control of buying and selling requiring identification for capitalism slavery.

Revelation 17:11 explains that this Beast "is the eighth, and is of the seven, and goeth into perdition" (KJV). It is a continuation of the seven-headed creature described in Revelation 13, but it is in some ways like an eighth head on that creature since it begins after the last head of the Beast of Revelation 13 receives a "deadly wound." The seven heads of the Revelation 17 Beast are seven kingdoms (v. 10). They are the seven resurrections of the Holy Roman Empire, corresponding to the last seven of the "ten horns" of Daniel 7 and Revelation 13. The ten horns of Revelation 17 are also ten kings or kingdoms (v. 12). They give power to the final revival of the Holy Roman Empire and will be destroyed by Christ at His coming (v. 14), thus corresponding to the ten toes on the image described in Daniel 2. [tomorrowsworld.org]

Unicorn of biblical text is the ONE horned unicornis rhynosarus. [unicornsrule.com]

There is a unicorn that may of been seen by people before it went extinct. [wired.co.uk]

My family members take this shit literally

Satan described as being a dragon is probably the best one.