Mutable Genus Creatures

Creatures in the Tyranid army list are either a mutable genus or a genofixed species. A genofixed species is one which has been stabilised as part of the Tyranids' genetic repertoire and are normally creatures bio-engineered with a very specific purpose in mind, such as Tyrant Guard, Zoanthropes and so forth. In terms of evolution, the genofixed species are set and cannot be changed.

Mutable genus creatures are capable of being bio-engineered into new species in accord with the needs of the hive fleet. This means that the creature's weaponry and characteristics can be altered to create a new species different to that portrayed in the army list. By using the genetic modification procedure of adding biomorphs and weaponry you can create your own unique species for your hive fleet list. Note: When creating your own species, all biomorphs and bio-weapons must be shown on the model.

Mutable Genus List

The following creatures are mutable genus:

So, for example, I could decide to create a new hive fleet species list for Hive Fleet Arachnia using mutable genus to create new species as follows:

Swarm Tyrants (New species created from Tyrant genus) Harpies (New species created from the Warrior genus) Tyranid Warriors Lictors Termagants Deathgaunts (New species created from Gaunt genus) Nightgaunts (New species created from Gaunt genus) Scythe Swarms (New species created from Ripper genus) Biovores Razorfex (New species created from Carnifex genus)

This brings my Hive Fleet Arachnia swarm to a total of 10 species, four taken straight from the army list and six created from mutable genus stock. Note that although both Deathgaunts and Nightgaunts are created from the Gaunt genus they are still two separate species.

Tyranid Genetic Modification Procedure

Creating a new Tyranid species is undertaken via the following the[sic?] steps.

1. Select genus type. Genus which can be adapted are noted as being mutable as opposed to genofixed. Once a genus has been chosen, turn to the appropriate Genus Biomorph table.

2. Adapt the genus characteristics and weaponry. Each mutable genus has a list of possible biomorphs and bio-weapons available; you can choose up to the maximum number of biomorphs and bio-weapons indicated for the genus to create your new species.

3. Total the points cost of the biomorphs & bio-weapons and add it to the genus' basic cost to find the cost of your new species.

4. Fill in the new species on your hive fleet list and come up with a groovy name for it. When creating broods they must contain identically biomorphed creatures of the same species; the only way to get creatures with different characteristics into the brood is to include mutants. Whether or not the broods' bio-weapons must be identical is detailed in the Genus Biomorph tables.

It's important to note that although different creatures may be developed from a single mutable genus, each new creature is an extra species that will need to be added to the hive fleet's total number of species. Eg, Hive Fleet Arachnia includes two different sorts of Gaunts created using the modification procedure. The two different Gaunts are counted as two different species when it comes to totalling up the number of species in the swarm for the purposes of including mutants.

Hive Fleet List Force Organisation

Species derived from a mutable genus fit into the force organisation as follows.

Certain heavy genetic modifications to a species will change what category it occupies in the army list as shown below.