I have some snakes, wondering if I can transport them in my hold luggage.

I read PHMSA "Guidance and Criteria for Fireworks Novelties"

which says

"NOVELTIES: The following novelties may be transported as not regulated as explosives by surface modes when transported under the following provisions. When novelties are transported by aircraft, they must be classed as Flammable solid, inorganic, n.o.s. (novelties), UN3178. Novelties must be manufactured and packaged in accordance with the following:

Snakes and Glow Worms - Snakes and glow worms are pressed pellets of pyrotechnic composition that contain not more than 2 grams of composition per article. Upon burning, snakes and glow worms produce a snake-like ash that expands in length as the pellet is consumed. The chemical composition consists of ammonium perchlorate, nitrated pitch, asphaltum, and carbonaceous materials, snakes may not contain arsenic. Snakes and glow worms must be packaged in an inner packaging which contains no more than 25 devices.

Packaging: All novelty devices in their inner packagings must be packaged in strong outer packagings. The packages must conform to the requirements of § 173.24. The maximum gross weight of any strong outer package may not exceed 30 Kg.
Marking Requirements: Each package, and overpack if used, containing Novelties that conform to the criteria in this Letter must be plainly marked "NOVELTIES NOT REGULATED, EXCEPT WHEN TRANSPORTED BY AIR."

Modes of Transportation Authorized: Motor vehicle, rail freight, cargo vessel, passenger aircraft* and cargo aircraft* (*May only be shipped as Division 4.1). "

I found 173.24: http://www.setonresourcecenter.com/4...9/wcd00933.asp

but it's still not clear to me what the packaging requirements are.

My snakes are in packs of 5 sealed in cellophane inside small cardboard boxes marked "NOVELTIES NOT REGULATED, EXCEPT WHEN TRANSPORTED BY AIR."