Metatron is believed by some to be Enoch transformed into an angel. Some time ago on chat someone said that he is part of official Catholic dogma. However, I couldn't really confirm this with a cursory Google search as I keep running into stuff talking about Jewish beliefs. Thus, I'm wondering just how official Metatron is within Catholicism?
I am not a Catholic but I will try to answer anyway.
The term dogma has a specific technical meaning: it refers to a belief that Catholics are required by the Church to accept. There are many beliefs which are not dogmas, even if they are widely held to be true.
The book Fundamentals of Catholic Dogma by Ludwig Ott (1952) is a standard reference. He lists ten beliefs under angelology.
Among these, 1, 2, 8 and 10 are listed as "de fide", meaning true by reason of divine revelation; 4, 7 and 9 are "sententia certa", meaning theologically certain; 3 is "sententia communis", meaning commonly believed but not necessarily certain; and 5 is "certa" for the fallen angels and "communis" for the rest. No mention here of Metatron, or anything of the sort.
The Catholic Encyclopedia says under "Angels" that "no proposition touching the angelic hierarchies is binding on our faith". It refers to De Coelesti Hierarchia by Pseudo-Dionysus, and the Summa Theologica by Thomas Aquinas, as containing commonly accepted beliefs about the different types of angel; neither of these mention Metatron, or any figure fulfilling that role. All such writings are seen as speculative, and within the domain that theologians can legitimately argue about. Metatron crops up only in the encyclopedia entry for "Kabbala", but the context is explaining that it is a belief held within Judaism.
In conclusion, it seems that Metatron is very far from being Catholic dogma, or even a belief that many Catholics hold.
St. Michael, St. Gabriel and St. Raphael are the only named Archangels on the feast of the Archangels on September 29th.
We have no named angels except those three and no public revelation except the Bible, therefore no angel named Metatron.