Tiberium wildlife

Tiberium proliferation and its xenoforming effects have resulted in the creation of several unique mutant species. While the Forgotten and products of Nod Divination are Tiberium mutants, their physiology and intelligence makes them closer to humanity than results of immediate, uncontrolled mutation. Encounters between humanity and Tiberian wildlife have drastically decreased since the Firestorm Crisis, as GDI has taken measures to eradicate those populations of creatures that could pose a threat to civilians.

Visceroids
Results of uncontrolled, irregular Tiberium mutation, these organisms are essentially a large, unstable body mass, constantly changing their shape and never reaching a stable state. Parts of the original victim may be recognized within the Visceroid, but no way exists to bring the mutated one back.

The Visceroid is formed when a hapless living organism (typically a human) is overcome by Tiberium fumes and radiation and uncontrolled mutation of its body occurs. These creatures were the only example of tiberium fauna that existed as far back as the First Tiberium War. Visceroids have severely stunted cognitive functions; their only apparent purpose being absorbing any non-visceroid creature it can. To this end, they attack anything around them relentlessly.

A juvenile Visceroid is formed that can mature into an adult if it can merge with another "baby" Visceroid. The adult form is extremely hostile, aggressive and dangerous, attacking anything it perceives as a threat relentlessly and regenerates nearly instantly in Tiberium fields.

By 2047, these mutations have stabilized somewhat, possibly due to Tiberium evolving and changing its shape, and developed a protective shell with three appendages to move. This could also be a result of more advanced technology of the Scrin, as they are a side effect of Corruptor Tiberium spray.

Anecdotal reports exist that portray the Scrin Corrupter vehicle as being able to horrifically mutate humans into Visceroids. As the resultant Visceroids are hostile towards anything and everything this is likely to be an unwanted side-effect for the aliens.

Tiberium Fiend
The 'fiend' (latin classification: Canus Tiberius) is a horse-sized animal, resembling a dog. The flesh is blackish or red, and the back is covered with Tiberium crystals, which fiends launch at enemies, causing both damage as well as Tiberium poisoning.

Often, fiends bury themselves in Tiberium fields (the Tiberium on their backs concealing them) and lay in wait to attack Tiberium harvesters. They react to perceived acts of kindness, and The Forgotten have been able to actually "tame" a significant number of them for use as watchdogs. They have also been observed living in family groups.

Floater
Floaters, are a species of strange, jellyfish-like creatures that began to grow more and more prevalent as time went on as first phase of the Second Tiberium War drew to a close. Floaters floated over the battlefield, releasing Tiberium gas to move them through the air. The gas was dangerous to infantry - it could potentially turn infantry into visceroids.

Furthermore, the floaters' electric attack, which it used when in contact with the target, grappling and shocking it, was extremely effective against both vehicles and structures. The floater could even stop the vehicle it was attacking from firing. It was not seen in the Third War for unknown reasons. It is presumed that they died out.

It is unknown what manner of creature was mutated into the floater.

Veinhole

 * Main article: Veinhole

A veinhole "monster" is a bizarre mutation of unknown origin first encountered during the First Tiberium War, and was frighteningly common as of the Second Tiberium War, though numbers were drastically reduced in populated areas by the Third Tiberium War.

Tiberium "Crab"
In the beginning of recently acquired footage there is a shot of a Crab like creature for a few seconds. The Crab seems to be highly mutant like other Tiberium wildlife with a dark green shell and razor sharp points. It is seen enjoying its day in an unknown yellow zone Tiberium patch.