What is the only animal with a skull but no spine?

There's no evidence of yo-yos being used as weapons. However, In 1933, yo-yos were banned in Syria because many locals superstitiously blamed the use of them for a severe drought. (Both statements are from a Wikipedia article.)

@Dave Bair,

You appear right. I had found an article stating they were once used in the Philippine jungles as a weapon, but using AI to dig deeper, it responded with this:

No, there is no credible evidence that yo-yos were ever used as weapons in the Philippines.

The claim that ancient Filipino hunters used yo-yos with rocks attached to ropes to entangle animals' legs is an urban myth that has been debunked.[1][2] This myth likely originated from the success of Filipino-American entrepreneur Pedro Flores, who popularized the modern yo-yo design in the 1920s after immigrating to the United States.[1][2]

The earliest records of yo-yos date back to ancient Greece and China, where they were simple toys.[1][2] While improvised weapons resembling yo-yos may have existed historically, the modern yo-yo design with a thin string attached to a lightweight object is not a practical or effective weapon.[3]

The word "yo-yo" is believed to derive from the Ilocano language of the Philippines, referring to the toy's back-and-forth motion.[1][2] However, there is no evidence that Filipinos used yo-yos as hunting weapons before Flores popularized the modern design in the early 20th century.[1][2][3]

In summary, while the yo-yo has roots in Philippine culture through its name and Flores' contributions, the claim that it was originally a Filipino hunting weapon is an unfounded urban legend.[1][2][3]

Citations:
[1] https://www.esquiremag.ph/culture/lifestyle/yo-yo-history-weapon-a00203-20181129
[2] https://www.reddit.com/r/FilipinoHistory/comments/hf4to7/mythbusting_yoyos_were_used_by_ancient_ph/
[3] https://www.youtube.com/watch?v=-hHveF49P9Y
[4] https://www.youtube.com/watch?v=RSFgJUzKmjA
[5] http://www.yoyomuseum.com/museum_view.php?action=profiles&subaction=yoyo

Added later 06 min 50 s:

Bruce McCrory wrote:

Hagfish. Saw a children's science program about the massive slimy mess they make.

Hah! Yes, I think you fit the description.

The hagfish is a unique marine creature that has a skull but no vertebral column or spine, making it the only known living animal with this characteristic[2].

Some key facts about hagfish:

- They belong to the class Myxini and order Myxiniformes, eel-shaped jawless fish[2].
- They have elongated, eel-like bodies covered in loose, naked skin without scales[2].
- They lack jaws, fins, and have only rudimentary vertebrae[2].
- Their most distinctive feature is their ability to produce large amounts of slime from glands in their skin as a defense mechanism[2][3].
- They feed on dead and dying fish by tying their tooth-like rasping structures into the flesh and ripping it apart[3].
- They have poor eyesight with only simple eyespots, but an excellent sense of smell to locate food[4].
- They are found in temperate ocean waters around the world at depths from 30 to 16,000 feet[1].
- In Washington state, the Pacific hagfish is commercially harvested and exported live or frozen, mainly to South Korea where it is considered a delicacy[1].

So in summary, the hagfish stands out as the only known living vertebrate to possess a skull but completely lack a vertebral column, along with its notorious ability to rapidly produce copious amounts of defensive slime[2][3].

Citations:
[1] https://wdfw.wa.gov/fishing/commercial/hagfish
[2] https://en.wikipedia.org/wiki/Hagfish
[3] https://www.youtube.com/watch?v=_8FVpj0p-iU
[4] https://www.montereybayaquarium.org/animals/animals-a-to-z/pacific-hagfish
[5] https://www.theatlantic.com/science/archive/2019/01/hagfish-slime/581002/

Added later 31 min 27 s:

FYI, the above, produced by Perplexity AI, originally responded that no animals fit that description. I had to prod it a bit by asking "What about the hagfish?" where it amended its answer as above.

Woody Barker, our friendly K9AI (using ChatGPT), had no such problem, immediately responding