Basic undead types in fiction

Revenants

A person who's returned from the dead but there isn't necessarily any rotting, meat or blood lust or even immortality. Revenants are the basic back in the flesh undead and are the historical representations of both zombies and vampires, depending on their extra characteristics. The are often associated with or from Romania. Sometimes revenant is just another term for undead.

Zombies

There are various subbranches and causes but zombies are the almost or completely spiritless dead with minimal brain function and bodies that rot. Originally zombies were commanded by their summoners.

Vampires

Either always a vampire or a human turned. Vampires are technically immortal and drink blood. They can be killed in a variety of ways but if left alone they will not die unless exposed to the sun. Even refusing to eat is unlikely to kill them unless this is specifically referenced for a plot.

Ghosts, phantasms, and spectres

These are those who return or remain in spirit only while their bodies are buried or cremated as usual. Sometimes cremation or a proper religious burial is written in as a way of destroying the spirit or sending it on to the afterlife/putting to rest. These are less likely to be violent or able to manipulate the physical but can be either benevolent or malevolent. They range from see-through to clearly visible but none have a physical presence.

Shades, spirits and devas

Shades are ghosts acting under the command of their summoner. 

Poltergeists

Violent malevolent ghosts able to manipulate the physical. Spirits and devas have a little extra ability in the way of magic and are a good choice for placing within a body, if needed, as they have some control.

Ghouls, ghasts and wights

These are more substantial than ghosts or shades. They are vicious and malevolent spirits who have a strong physical presence. Their touch drains the energy of a person and both ghouls and ghasts tend to tear their victims to shreds. Wights are related to the ghouls and ghasts, they have claws that suck the life out of all living things. They have the ability to eliminate a person's memories and skills, leaving them living zombies or like newborns. All are quite capable of working in groups or at least congregating. It is often the case in modern fiction that ghouls have a physical form much like that of zombies but stronger and less human.

Wraith and Hraithes
A wraith is often a ghost or image of someone seen shortly before or after their death. They can also be depicted as strong and lasting spirits who suck the life from anyone who touches them. A hraithe is the spirit of a vahnatai mage reluctant to move on or rest. The hraithe is often jealous of the living and still magical to a certain extent.

Walking skeletons and vahnavoi

Walking skeletons have basic human strength while vahnavoi are imbued with the extra strength and skills of a sword fighter. They are usually summoned from the grave just as zombies can be.

'Frankenstein's' monsters 

Scientifically reanimated and stitched together monsters that resemble humans, they often have the thoughts and feelings of young children or the mentally disabled due to brain transplant procedures and oxygen deprivation at death. They are usually called 'Frankenstein's' monsters although the maker may change.

Mummies

Bodies missing parts and often skeletal, mummies are much like zombies except they've been dormant for a long period of time, they don't bite and aren't made from contagion but may be created by a spell, may act upon a summoners orders or carry out a curse. They do not rot as zombies do but rather decay as though still in a dry enclosed climate.

Magical reanimations

For these, the or a spirit is returned to the flesh. Problems usually occur, such as the body rots or the spirit fades or can wander. Spirits other than the original body's may be used, even demonic spirits. The magic used is often depicted as black or at least dangerous to the practitioners.