This pet is my main go-to pet now a days. It is basically like having an immortal mini [Saryn] that does Viral damage (thanks to [Viral Quills]) and a mini [Trinity] who constantly heals you, in your pocket at all times.
[Hunter Recovery] synergies with [Viral Quills] so that it can heal heal you as its spores spread and do damage.
Furthermore, [Synth Deconstruct] Synergizes with [Viral Quills] too so you will be dropping health orbs everywhere.
In addition, There is plenty of Damage (Maul and Bite) and Tank (health link and armor link) on this build to actually be useful in higher level areas too (that why they are not "devolving" constantly and not buffing you).
Fetch and Primed Animal Instincts are a must for utility of making a pet useful.
This also adds Synth Deconstruct to occasionally drop health orbs for you.
Lets not forget ALL vulpaphyla's are immortal, thanks to Sly Devolution so this pet will be around.