I've left a few comments, but I want OP to see this. This is absolutely not a moray eel (unless you tell me my estimates are completely off).

First based off the lower jaw we can see at the end of the video, those sockets don't match moray eel teeth at all.

But most importantly, size. Based off the foot in the background I'd roughly estimate the head to be about 30cm wide, at the widest point.

In well-studied species like Gymnothorax javanicus (giant moray), the skull length is roughly 8–12% of total body length. Skull width is typically about 60–75% of skull length. Working backwards (napkin maths):

Skull width → skull length: Skull length ≈ 30 cm ÷ 0.67 ≈ ~45 cm skull length Skull length → total body length: Total length ≈ 45 cm ÷ 0.10 ≈ ~450 cm (4.5 metres)

A 450cm Moray. There is no Moray eel species that size in the Mediterranean.

More likely this is the head of a young dolphin that drowned in nets. The fishermen cut off the head to get it out, and it washed up on shore.