It is most likely that the imagery of the "nine formed god" referred to in the papyri would not be public knowledge. In terms of the greek mysteries, nine is a number intimately linked to knowledge of the "cosmos". However knowing what this particular "god" represents in this particular papyrus would also be helpful, and if you look at the rest of the passage here, it gives a hint to the context:
Instead of the popping noise and the hissing [sound in the name] draw on the first part of the natron a falcon-faced crocodile and the nine-formed god standing on him, for this falcon-faced crocodile at the 4 turning points [of the year] greets the god with the popping noise. For, corning up to breathe from the deep, he goes "Pop, pop, pop," and he of the 9 forms replies to him antiphonally. Therefore, instead of the popping noise, draw the falcon-faced crocodile, for the popping noise is the first element of the name. The second is a hissing. Instead of the hissing [draw] a snake biting its tail. So the two elements, popping and hissing, are represented by a falcon-faced crocodile and the nine-formed god standing on it, and around these a snake and the seven vowels.
The 4 turning points of the year are a reference to the equinox and solstice days. Since the crocodile has a falcon face, he could be referencing Horus as the reborn or victorious Sun, "coming up to breathe from the deep". He goes "pop, pop, pop" and is answered by the nine formed god "antiphonally", or, in a sing-song manner. The nine formed god is linked to the crocodile and stands upon him, and answers when he calls, in a musical way. This could be a reference to many different things. However it may be interesting to note this particular relation of the 3 "pops" to the 9 formed god. In particular:
The Roman scholar Varro (116–27 BC) relates that there are only three Muses: one born from the movement of water, another who makes sound by striking the air, and a third who is embodied only in the human voice. They were called Melete or "Practice", Mneme or "Memory" and Aoide or "Song". Three ancient Muses were also reported in Plutarch's (46–120 AD) Quaestiones Convivales
However, the classical understanding of the Muses tripled their triad and established a set of nine goddesses, who embody the arts and inspire creation with their graces through remembered and improvised song and mime, writing, traditional music, and dance. It was not until Hellenistic times that the following systematic set of functions was assigned to them, and even then there was some variation in both their names and their attributes: Calliope (epic poetry), Clio (history), Euterpe (flutes and lyric poetry), Thalia (comedy and pastoral poetry), Melpomene (tragedy), Terpsichore (dance), Erato (love poetry), Polyhymnia (sacred poetry), Urania (astronomy).
Diodorus also states (Book I.18) that Osiris first recruited the nine Muses, along with the Satyrs, while passing through Ethiopia, before embarking on a tour of all Asia and Europe, teaching the arts of cultivation wherever he went. According to Hesiod's account (c. 600 BC), generally followed by the writers of antiquity, the Nine Muses were the nine daughters of Zeus and Mnemosyne (i. e. "Memory" personified), figuring as personifications of knowledge and the arts, especially literature, dance and music.
This is even more interesting when noting the following:
The Muses were venerated especially in Boeotia, in the Valley of the Muses near Helicon, and in Delphi and the Parnassus, where Apollo became known as Mousagetes ("Muse-leader") after the sites were rededicated to his cult.
Which would indicate another reference to a Sun-god of knowledge akin to Horus. It is also worthwhile to note that the sounds of the "pop" and the "hiss" seem to be referential to a movement of time. In other words, the three "pops" are given at a changing point, and thus a reference to birth or death, a transition - whereas the "hiss" is represented by the Ouroboros, or the snake biting its own tail - which is a reference to eternity, or the endless cycle of life.
However, it seems the most specific reference to the nine formed god is in the following passages, when he is addressed as such:
I call on you, who are greater than all, the creator of all,
you, the self-begotten, who sees all and are not seen.
For you gave Helios the glory and all the power,
Selene [the privilege] to wax and wane and have fixed courses,
yet you took nothing from the earlier born darkness,
but apportioned things so that they should be equal.
For when you appeared,
both order* arose and light appeared.
All things are subject to you, whose true form none of the gods can see;
who change into all forms.
You are invisible, Aion of Aion.
... Through you arose the celestial pole and the earth.
And it is essential to note the following in regards to this passage, which is revealed in the footnotes of the translation:
This invocation and the following (138-53) are essentially identical, both being variations of an old Egyptian hymn in which the rising sun is greeted by the sacred animals, each kind making its appropriate noises. In both invocations the sun god has been made the creator and sustainer of the world, and the songs of the animals are preceded by and partly fused with the songs of the angels, many of whom are Jewish. In both, the same angels and the same languages appear in the same orders. The roles given the god and the angels, and the personnel, help explain the attribution to Moses, the more so because these two invocations are the most important elements in the text - the active agents which make the deity appear.
*Here "order" translates the Greek κόσμος - which means also "the cosmos."
And then finally we have a few more references to this "god" by other "names" in various animal forms:
I call on you, lord, in 'birdglyphic": ARAI; in hieroglyphic: LAILAM; in Hebraic:"ANOCH* BIATHIARBATH BERBIR ECHILATOUR BOUPHROUMTROM; in Egyptian: ALDABAEIM; in 'baboonic': ABRASAX: in 'falconic': '"HI CHI CHI CHI CHI CHI CHI TIPH TIPH TIPH; in hieratic: MENEPHOIPHOTH CHA CHA CHA CHA CHA CHA CHA." Then clap 3 times, go "pop, pop, pop" for a long time; hiss at some length.
In this particular passage, the footnote of the translation is most telling indeed, namely:
*In spite of the claim that this is Hebrew, the first word is a transliteration of the Egyptian word for "I AM" which is "anoch". A similar Hebrew word "anoki" has the same meaning. The author seems to have known Hebrew and Egyptian badly enough to mix them up. See glossary..."
Which brings us "full circle" to the aspect of a god of knowledge, or indeed - "knowing" itself. In other words: gnosis. This invocation above reveals a basis for this text; and shows that it is clearly derived from some school of ancient systemology which blended greek, egyptian, jewish and persian sources of myth and knowledge. This is commonly referred to today as "gnosticism" - although Im sure you are already aware that there were many schools of this kind, and not all of them shared the same ideas. However they did tend to have some basic points in common. In particular, the highest "god" is usually awareness or the "I AM" principal itself - that which orders all things and brings them into being by virtue of its own existence and which is the "self-begotten One". Also the type of external knowledge which seems most venerated in such schools is that which refers to motions of celestial objects and especially the sun and moon, but also astrology in general. This is probably due to the fact that the scientific knowledge resulting from observations of the night sky was one of the first systems of its kind to be passed down through the generations.
Of course there are many other aspects of the number 9 in regards to the greeks, and especially anything derived from pythagoras - and of course by extension: egypt, persia, india, and china. It is a number of completion in regards to the base-10 system, which was symbolized by him in the form of the tetraktys. In other words, nine is the last numerical value, which therefore contains all forms preceding it by means of addition. Its use in regards to constructing visual forms is a cornerstone to understanding many kinds of sacred geometry. This is also why the number nine appears so frequently in other forms of western esotericism such as the freemasons and so forth.
Finally - I thought you might find these images interesting as well, in relation to the stelae above: