Vermivorous the Invincible

Vermivorous the Invincible is the name of the highest possible level of varkid in Borderlands 2, with the alternative title of Supreme Badass Varkid. Varkids that evolve to this stage are regarded as raid bosses. Vermivorous can only spawn in True Vault Hunter Mode or Ultimate Vault Hunter Mode.

Evolution

The chances of any given Varkid evolving depend on the number of players present in the session. It is possible to spawn Vermivorous with only one player, although the chance of it happening is very low. It cannot spawn on Normal Mode, regardless of the number of players present.

Contrary to popular belief, varkids do not need to be harmed in order to improve the chance of evolution, nor do varkids that kill other enemies (e.g. spiderants or buzzards) have higher evolution rates.

It takes five morphs for a Larval Varkid to become Vermivorous the Invincible. Chubby Varkids are an alternate evolution of Badass Varkids and have the same chance to morph into Super Badasses. The following tables show the morph chance for each evolutionary step:

Evolution Chance - Normal Mode	1 Player	2 Players	3 Players	4 Players
Larval → Adult	60%	70%	80%	90%
Adult → Badass	30%	40%	50%	60%
Badass → Super Badass	10%	20%	30%	40%
Super Badass → Ultimate Badass	0%	1%	2%	3%
Ultimate Badass → Vermivorous or Supreme Badass	0%	0%	0%	0%

Evolution Chance - True Vault Hunter Mode	1 Player	2 Players	3 Players	4 Players
Larval → Adult	70%	80%	90%	100%
Adult → Badass	40%	50%	60%	70%
Badass → Super Badass	20%	30%	40%	50%
Super Badass → Ultimate Badass	10%	20%	30%	40%
Ultimate Badass → Vermivorous or Supreme Badass	7.5%	10%	11%	12%
Larval → Vermivorous or Supreme Badass	0.042%	0.24%	0.7128%	1.68%

Evolution Chance - Ultimate Vault Hunter Mode
The chances seems to be even higher, but the exact percentages are currently unknown.

Evolutionary Limit

Varkids have a reliable timer that determines whether they are going to evolve or not. This timer should be taken into consideration to decide when the team can kill them. If a varkid doesn't evolve after the duration provided in the following table it won't evolve at all.

Varkid Form	Larval	Adult	Badass	Super Badass	Ultimate Badass
Time to morph into pod	10 seconds	20 seconds	30 seconds	60 seconds	120 seconds

For example, an Ultimate Varkid that hasn't evolved after 2 minutes, will not evolve, and can be killed without penalty.

It hasn't be confirmed by a reliable source if the varkids need to be active in combat or not for the stated times. Some sources^[1] state that the timer will reset to zero if a varkid leaves combat before it is complete.

Other sources^{[citation needed]} state that it has no effect and that after the first time contact is made, the timer continues even if the varkid leaves combat (as noted by their icon disappearing from the minimap. If this is the case, then the varkid will then instantly hatch upon detecting a player again, provided that enough time has passed.

Spawn Strategy & Fight

Vermivorous has more health than Terramorphous the Invincible, but since the fight does not restrict use of cover, buying more equipment or respawning (provided the varkids stay combat active to avoid despawning), no special strategy is needed. Players will probably spend more time trying to spawn Vermivorous than fighting it.

Vermivorous is similar to a regular Ultimate Badass Varkid, albeit stronger; it can provide a barrage of corrosive balls, summon explosive small varkids that track the characters, similar to missiles, and stomp targets in close vicinity. Vermivorous can fly (with no clear preference between ground and air), and while it cannot burrow underground like the Super Badass Varkid can, it can nevertheless run across the ground in short, blinding bursts of speed when attacked that almost make it look as if it has teleported to anyone attacking it.

Areas in which large numbers of varkids are found are ideal for getting Vermivorous to spawn. Varkids can be found in abundance within the Caustic Caverns and the Tundra Express - Farmhouse, both of them with convenient Fast Travel stations near the varkid spawn areas. It is also possible for the Ultimate Badass Varkid which spawns in the Creature Slaughter Dome to level up to Vermivorous the Invincible, but this requires the corresponding DLC.

A good strategy to spawn Vermivorous within Caustic Caverns is to have one team member aggro the group of varkids in the initial area, and run to the nearest crystalisk, while the rest of the team waits by the Fast Travel station. After the varkids start to fight the crystalisk, the team should regroup at a safe distance where they have the group in sight (just after crossing the initial gate, near the truck, is a good spot to watch the action). Even on Ultimate Vault Hunter Mode, varkids and crystalisks should take an extremely long time to kill each other (the varkid AI will not target the crystallized legs and the latter are usually unable to kill the former beyond the adult form). Shooting at them is not advised because that could lure dangerous high level varkids towards the team. If they don't evolve in accordance to the timers above, the team can kill the varkids and/or lure more of them to the crystalisks. Caustic Caverns has an ammo dump machine next to the fast travel station, giving an advantage over Tundra Express as players are more than likely to run out of ammo during the fight.

The Tundra Express Farmhouse provides another area with large numbers of varkids. The varkids cannot enter the farmhouse, so players can take cover inside, though they will still be vulnerable to the Badass Varkid's projectiles. As there aren't any closer enemies, it is also easier for varkids to leave combat and become inactive but after some minutes a group of buzzards will appear. Even if this is a less optimal choice than Caustic Caverns, it provides an alternative to travel back and forth for teams trying to spawn Vermivorous.

It is possible to kill Vermivorous instantly if the team is able to lure in in front of the train that runs through Tundra Express.

It is also possible to instantly kill Vermivorous in Caustic_Caverns near the first fast travel station. If the team manages to close the first sets of doors while Vermivorus is standing near them, immediate opening of the same door will result in her death.

Notes

A hotfix released on March 12 increased the quality of loot vermivorous drops once killed.
A legendary item is almost guaranteed to drop, including Norfleet.
The 'suicide varkids' frequently released by Vermivorous can be used to achieve a Second Wind.
Vermovorous has a surprisingly non-aggressive AI, even when attacked, and as such can sometimes decide to wander off from the battlefield if it is not regularly attacked. Players are advised to try and keep track of the monster and keep hitting it, even if it is risky to do so.
- If Vermivorous escapes the players' sight, whether because it has wandered off or has been lured far away from the immediate area of combat by enemies, it has a good chance of vanishing into thin air, frustrating players' efforts to kill it and collect the resulting loot.
Within Caustic Caverns there is a small alcove located in the very back of the small area that players arrive in, immediately south of the vending machines and Fast Travel station. The archway next to the small door provides almost complete protection from Varkids of every evolutionary stage -Larval and Badass Varkids will go there only very, very rarely, Super Badass Varkids won't go there at all, and the flying varkid varieties from Adult to Vermivorous will sometimes follow a character there, only to 'clip' inside the ceiling of the arch, which will in turn render their most of their acid spit attacks useless.
The small, narrow doorway which is the top level entrance/exit to Dahl Deep Core 06 (this doorway being a small distance away from the 'cave' in which arrivals to the Caustic Caverns first appear) has a thin door frame inside which provides 100% protection from varkid attacks of every sort; however, players who try to take advantage of this hiding spot - and there is literally room for only one player to take advantage of this full immunity - may find it difficult to impossible to chase after a wandering Vermivorous should the need arise (the amassed varkids at the door will not only provide a physical obstacle, they will also use their close-range melee attack to drive the Vault Hunter back).
As Vermivorous is not a fixed or scripted spawn, it is possible for other varkids to mutate into Vermivorous, even if one is already spawned. Although very rare, this can lead to multiple Vermivorouses spawning in one area, particularly if the area has many varkids.