This is my default Panzer Vulpaphyla Build.

Explanation of Mod Choices:

• [Primed Animal Instinct]: Great Utility providing you a free 33m Enemy Radar as well as a 55m Loot Radar, although usually Enemy Radar is more useful than Loot Radar.
• [Primed Pack Leader]: Not a mod that has to be equipped. It is more of a QoL by enabling you to keep your pet alive using a melee if it only took slight damage to health.
• Synth Mods: primarily because of Utility they provide the player: most Endurance builds use some sort of primer and then a main damage dealer. This enables the primer to be reloaded while you deal damage, enabling a higher upkeep of DPS. In addition to that, on some builds a health orb provides utility and is therefore very useful to have a higher chance of dropping.
• Viral Quill: Additional Viral procs are possible, increasing your damage output further.
• [Sharpened Claws]: Not taken for the damage. Its true purpose comes from the second part "sunders armour by 120%", this means that whenever the companion attacks an enemy with that attack it strips all armour of that enemy, enabling a higher damage output against that enemy for the player.
• Panzer Devolution: Used to turn your companion immortal, saving you the risk and damage loss of reviving your companion.
• Hastened Deflection: Used to provide a minor manner of shield gating to the companion, increasing survivability slightly.
• Link Health: Used to increase the health pool. Depending on health of the Frame consider using Enhanced Vitality instead for a bigger increase in health. This hopefully ups the survivability slightly.
• Fetch: Utility mod by picking stuff from further away up, great QoL mod.

Alternative Mods to consider:

• [Martyr Symbiosis]: This increases your own survivability, with [Panzer Devolution], this should be available about every 30s, although if you require it that often, i would consider rethinking the build of the frame, perhaps add in some CC or other survivability.

Note:

All Primed mods can be replaced with their normal counterpart, although i would recommend trying to update as soon as Baro got these mods in his inventory, although I would prioritise Primed Animal Instincts over Primed Pack Leader, since the Utility/QoL that Primed Animal Instincts provides is more valuable in my opinion than the one [Primed Pack Leader] provides.

All mods should be written in Italics. If you have any questions write them and i will try to answer them ASAP.