Since a normal Sim cannot become a Servo or Bigfoot, an Alien-Servo or Alien-Bigfoot is not possible. This usually results in the creature having a different color skin tone for example, a vampire-alien hybrid will have a turquoise skin tone.

The Alien life state is just a skin tone and different genetics - therefore it can be coupled with any other life state that a normal Sim can be transformed into. The Sim will be able to go through certain objects and talk to other ghosts, but cannot go through walls. This hybrid is essentially the same as a normal Sim who has cast the 'Shed Your Skin' charm, as a zombie in The Sims is a Sim with a special skin tone and no personality points. The charm allows a Sim to turn into a controllable ghost for a period of time. With Makin' Magic, this 'hybrid' could be controlled when a zombie casts the 'Shed Your Skin' charm. The zombie life state was gained when a Sim died but was resurrected by the Grim Reaper as a zombie. Zombie-Ghost: In a sense, this hybrid existed in Livin' Large, but was not controllable. However, if the player has both Livin' Large and Makin' Magic installed, an early type of hybrid may be possible: Life states and hybrids were not clearly defined until The Sims 2 and The Sims 3. In The Sims and its expansions, life states were not very well defined.

Sims 4 vampire skin tones