Modified Micheal Cole Z13 solution.

Well actually, i am going to ripoff, ermm, i mean riff off, Michael Cole’s solution from 10years ago
Cole: https://zodiacrevisited.com/my-name-is-cipher-solution/

Micheal Cole presents his full solution as:
I AM [the Zodiac] . _ . X . _ M I X

~~~ The modification ~~~

As per Cole, the 1st underscore and the ‘X’ are the initials (forename, surname) of a name
So i think we can change the 2nd underscore to an ‘a’ resulting in:

I AM [Zodiac] . [forename] . [surname] . aM I [surname]

then it links nicely to “I am mildly cerous” on the next line.

This solution responds to Dr. D.C.B.Marsh’s challenge by giving Z’s name initials yet also reveals nothing.

[+] It keeps the glyph count 3 part symmetry of 4-5-4
[+] Has its own symmetry of “I am”, “am I”
[+] Ties into “I am mildly cerous”
[+] Reveals nothing about Z, just like the 408+340 (though this is a + point for Z, not for us )

[-] Does not tie into “My name is —” ( Though that long dash is peculiar )
[-] No question mark after the proposed “am I”

~~ An expanded full solution ~~
split Z13 into 3 parts

AEN@ .K.M. *NAM
iam@ .K.M. amiM

Key = {A:i, E:a, N:m, K:K, M:M, *:a, },
@ = Zodiac glyph ,
* = Inverted Aries glyph

I am Zodiac [.K.M.] am I Surname ?

–Zodiac , expanded form of Zodiac glyph
–? Should be in the cipher for grammar reasons, but is not
–K corresponds to letter initial probably a First name/ forename (culturally dependant)
–Surname corresponds to the 2nd initial, in this case ‘M’

~~ Notes ~~
“My name is —” could be the title of the cryptogram, specifically directing Prof D.C.B. Marsh to this cipher.

D.C.B. Marsh’s name has 3 periods in it … coincidence ?? I like to think its a reference to to D.C.B Marsh’s name.

M.Coles says the 8-ball glyph is a taurus symbol and its unused elsewhere on all Z’s ciphers
therefore it has a special significance – that is, it is a letter/word separator, like a space, period, etc.
None of Z’s ciphers so far as is known use a letter/word separator except maybe this one.

Super speculative is the philosophical angle of “I am Zodiac … am I Surname?”
Is Surname a character played by Zodiac ? Is Zodiac another personality of Surname ?
–In the “Death machine” letter dated November 9th 1969, Zodiac says;
“I look like the description passed out only when I do my thing, the rest of the time I look entirle different.”
Is it only Zodiacs appearance that changes or does his persona change too?
Will the real Zodiac please stand up. 🙂  

The envelope has a repeat of the word ‘Editor’ rotated 180 degrees.
https://zodiackillerciphers.com/wiki/index.php?title=Unsolved_13-character_%22My_name_is%22_cipher
–Could be a clue to this z13 or a clue to the z408 or nothing.
–Some of Z’s other envelopes have peculiarities,
not sure if those peculiarities have been studied, they probably have.

To be clear i am not saying this is the solution, it’s just another speculative attempt.

I kinda like the way it gives possible Name initials whilst at the same time gives nothing.
Credit to Micheal Cole, i just added a little tweak and made a messy post.