The genetic splicer can be found in both Creatures 2 and Creatures 3. On both versions you load two different creatures (Norn, Ettin or Grendel) into the machine and press a button or switch. The two creatures' dDNA is then cut apart and mixed together to create a single new creature. The original two creatures are killed in the process. In Creatures 2, they still appear in the Chronicles as being alive, and are not registered in the graveyard. There is, however, a glitch in Creatures 2 which allows you to save one of the victims of your genetic experiments. If you watch the cages carefully after starting the splicing process, you will have a short time after the purple flashes appear to press the button on one of the cages. Timing is critical, but if you press the button quickly enough after the flashes start, the flashes in that cage will freeze and the creature in the cage will be saved while still becoming part of the resulting spliced creature.
If this method goes wrong, however, you can end up with the purple flashes stuck, the creature unable to get out. If the splicer is re-run, it will create an egg that will never hatch.
In both games the splicer must be activated by pressing switches or collecting power-ups.
In Creatures 2, creatures that are old or dying may be 'saved' by putting them in the splicer on their own. The original will be destroyed, and a fresh egg containing a clone of the creature will be produced.
In Creatures 2, when the family tree of the new creature is examined, you will notice that the parents are the two creatures that you combined. It will also say mother and father on the birth certificate, regardless of genders of the original creatures (currently not tested in Creatures 3).
Creatures Online would have included an applet which would have allowed players to create their own Norn genomes rather than choose from a list of breeds. The player could also randomize what they wanted their Norn to look like. As shown in the demo, whenever the player's Norns reproduce the player could choose what features are inherited from the parents using sliders to control each future, if they wanted the Norn to more closely resemble one parent than the other
The first part of the Gene Splicer allowed the player to change the physical appearance of their Norn in several ways:
- Pattern Layout - Controls the layout of the Norn's fur patterns
- Fatness - Controls how fat or thin the Norn is (this doesn't appear to be modifiable with the player's first Norn(s))
- Fur Length - Control how thick or thin the Norn's fur is
The second part allowed the player to change their Norn's fur colour and/or patterns:
- Eye Color - Changes the colour of the Norn's eyes
- Fur Base Color - Changes the base color of the Norn's fur
- Fur Pattern Color - Changes the colour of the Norn's fur pattern
- Fur Detail Color - Changes the color of the Norn's fur details
As of June 2012, this was the main mechanism by which the players would be able to edit the genome of their norns - focusing on the appearance of the norn. There were no specific plans for a Genetics Kit.
At one point, Fishing Cactus considered implementing a skill system, to get the Norns to take care of plants, play with critters, repair toys and machinery etc. Skill at these tasks was intended to improve the norns' abilities and was meant to be inheritable by children. The stats were coded into genes, storing the value of each stat so that they could be inherited.