Traits

Octopus tentacles/octopus arms emerge from the head - may have 6-10 tentacles, but 8 is the most common amount.

Jellyfish tendrils and a soft, jelly-like "hat" on the head. These tentacles are not prehensile and cannot move on their own; instead, they rest like hair would. Can be venemous.

Squid-like  pointed"hat" and 8-10 squid arms and 2 tentacles. Tentacles stand out by being wide with suckers at the end, while squid arms are generally shorter, thinner, and taper off at the end.

Cuttlefish-like pointed "hat" with 6-10 short arms, may have 2 tentacles.

A shelled "hat" with shorter tentacles emerging from it. Can have up to 90 thin tentacles - though it can have much less than that for the sake of stylization.

This mantle resembles a Portuguese Man o' War. The top part of the mantle is filled with gas and can be used to float on the surface of the water. Tentacles are a mixture of curly and straight and tend to grow quite long.