Just How Often Did This Come Up?

To help round out a few of my thoughts on ancient Mesopotamian snake omens, I reread tablets 22 through 26 or at least the nearly complete tablets 22, 23 and 24 and what remains of tablets 25 through 26 of Šumma Alu ina Mēlē Šakin. Somehow this little gem from Tablet 23 escaped my memory from earlier readings:
91) If a 7-headed snake (MUŠ 7 SAG.DU.MEŠ-šù) is seen in a man’s house, the owner of that house will escape hardship.
Note the positive apodosis. Snakes in one’s house are seldom a good thing but a seven headed snake in one’s house sure is. Also note the seven headed snake that Ninurta brought forth and hung in the Sumerian text “Ninurta’s Return to Nibru,” 40 and 63.
This isn’t just a case of the diviners trying to be thorough with regard to snakes with various numbers of heads. The omen is in the middle of a set of snake omens having to do with snakes that are seen doing this or that in a man’s house and not in a series of omens dealing with multiple headed snakes.
There is another case of an omen concerning a seven headed snake in the poorly (and uncertainly) witnessed Tablet 26. It is in a short sub-series that may refer to at least one other six or seven headed snake as well as a two headed snake. The apodoses are all missing from the witness (K.6294). The complete sequence including the abrupt change in theme in the following omens is interesting.
1) If a Bašmu is seen [. . ]
2) If a Mušgallu (literally “great snake” in Sumerian) is seen [. . .]
3) If a 2-headed snake (MUŠ 2 SAG.DU.MEŠ-šù) is seen [. . .]
4) If a 7-headed snake (MUŠ 7 SAG.DU.MEŠ-šù) is seen [. . .]
5) If a 7-tongued snake (MUŠ 7 EME.DU.MEŠ-šù is seen [. . .]
6) If a snake kills a temple steward [. . .]
7) If a snake kills a tortoise(?) [. . ]
The next forty omen protases deal with a snake killing something or other.
Interestingly, Bašmu is a mythological horned snake and the Akkadian word for the constellation Hydra. One text, Sumer 13 93:17f (TIM 9 66), tells us that Bašmu had six mouths, seven tongues and seven . . .-s on its belly (see CAD S, 204). Note the 7-tongued snake in omen 5 (see CAD S 407). Bašmu also indicates some kind of plant (see CAD B, 141-42). The Sumerian loan Mušgallu, here spelled out (muš-gal-lu4) in a text that otherwise has an extremely high density of Sumerograms, is also a mythological snake (see CAD M/2, 269).
Again, there is no real attempt at completeness when it comes to multi-headed snakes here. My guess is that the first 5 omens are organized around the idea of mostly mythological snakes that could be a issue if encountered in real life and therefore needed to be taken into account just in case one show up unannounced. In so far as there is completeness, it involves taking into account mythological snake types and not your everyday variety (multi-headed) snakes.
We also see the mušgallu and a two headed snake in lines 13’ and 14’ of K.8038, presumably part of Tablet 25:
14’) [If a Muš]gallu is seen [. . .]
15’) [If] a 2 headed [snake] is seen [. . .]
The writing, in so far as it is readable, is identical to that of omens 2 and 4 of K. 6294 (Tablet 26).
In BM 78960, likely part of Tablet 25 or Tablet 26, we read:
15’) [If a Mu]šḫuššu (MUŠ.ḪUŠ) is seen, that man will become ri[ch].
16’) If a Bašmu snake is seen, that man will become important.
Mušḫuššu is a Sumerian loanword for some kind of purely mythological dragon or monstrous creature, sometimes represented in clay, stone, bronze or even gold. It has some snake like features, scales and head for example, but it also has feline and eagle features. Not something that one is likely to encounter wondering around in one’s house. Mušḫuššu also designates a constellation somehow apparently associated with Hydra and therefore likely related to Bašmu. These two omens seem to be associated by the reference to mythological snakes in their protases. Note that seeing these snakes (MUŠMEŠ) is a good sign for things to come.
As far as I can tell there are no omens concerning 6-headed, 5-headed, 4-headed or 3-headed snakes anywhere in the extant corpus. Yes, Bašmu might be an exception but he is not called six headed or even six mouthed in any extant part of series Šumma Alu ina Mēlē Šakin.
There may also be an omen concerning a single headed snake with two bodies (Tablet 24, omen 26).
“If a snake is 2 joined together (MUŠ 2 ti-iṣ-bu-tu-ma) and its head [. . .] will be dispersed.”
But it’s hard to know exactly what MUŠ 2 ti-iṣ-bu-tu means. Another extremely lacunose witness (K.13981) doesn’t read ti-iṣ following the 2 (MIN). Freedman, 65, speculates that this witness might read the DIB sign following the 2 (MIN). This would simply be the ideogram for ṣabātu, the verb most closely associated with tiṣbutu, “to seize, captivate, hold” or the like. So if this witness does read DIB here, it really isn’t much help in our understanding.
I suppose I should look to see if any omens in series Šumma Izbu deal with snake birth malformations. I know that many of the Šumma Izbu omens deal with animal birth malformations but I’m not sure about snake malformations specifically. Then, such an adventure would take me further afield from my current abnormal interest. So would the pursuit of the rather obvious Geek parallels to much of this. But I do hate this kind of loose end.
References:

Freedman, Sally, If a City Is Set on a Height: The Akkadian Omen Series Šumma Alu ina Mēlē Šakin Vol. 2: Tablets 22-40 (Occasional Publications of the Samuel Noah Kramer Fund 19; Philadelphia: University of Pennsylvania Museum / Babylonian Section, 2006)