This is a large ORTHOCONE cephalopod, commonly called ORTHOCERAS.
These are animals related to the modern day octopus and squid. These creatures had a soft body and an internal “bullet shaped” structure that preserved as fossils. These creatures would lay down additional body segments as they grew and had a structure called a SIPHUNCLE that ran the length of the cone. The siphuncle could be pumped with air to keep the creature buoyant. These are found in the Atlas Mountains of Morocco.
This overall length is 7 inches and BONUS this one has the siphucle visible. There are also several smaller ones on the piece.