This first one I actually did a few months ago, based on a vampire character I was playing in a game set in the dark ages.
Sometimes the NPCs in the game are described as though a familiar actor is playing them. This is Major Neeson. The game we're currently playing is a mix between X-Files and X-Men, so his character is sort of a mix between Professor X and Asst. Dir. Skinner.
This is Rip Torn cast as Jonah White, an ex-CIA psi-ops participant and occult scholar. The group rescued him from Alabama river pirates and now he assists them with their paranormal investigations.
This scene was made mostly with photocompositing rather than straight up illustration. It shows one of the group racing to rescue his teammate, who was tricked and ambushed by a vampire they were hunting. You can see his body being lifted above the edge of a corn field on the far right, the vampire's claws extending through his chest right before he dropped him, turned in a crow, and pecked out his eyes.
This is Harkin, the vampire they captured after the attack. He can turn into mist to escape most prisons, so a weaponized shop-vac and the ultra-durable air-tight container he is held in had to be used to capture him.
This last one is a creature created using some kind of nanotechnology the group hasn't fully investigated yet. Their drool glimmers with tiny specks of metal, and their bite transforms the victim into one of them. One of the player characters was bitten, but his ability to psychically connect to and control technology allowed him to assimilate the nanobots into his body rather than be transformed.