Survivor
Overview
The Survivor is a NPC ally you can find during the mission Find survivors from another expedition from Technician Naylor (CoV, levels 35 - 40). He is the leader of the failed expedition you are looking for. He will be fighting a Chief Mentalist when you find him first, and must be freed so he can help you.
Once free, he will follow you and will attack any Hydra or Rikti in his aggro range. If your char is one of those stealthy types, free him last.
During my mission, the Survivor had slightly less hit points that a Lieutenant of the same level. He was probably a watered-down Boss class ally.
I have no idea if the mission would fail if he'd be defeated. His defense is relatively weak against the Toxic damage the Hydras use at range (like everyone else), but, being the Hydras weak against Lethal damage, his Melee damage output is fearsome, being able to defeat any Hydra he finds in a couple of seconds once he gets in Melee range.
Quotes
During the mission he will say the following:
Before combat: Lord Recluse will wipe you freaks from the cosmos!
Combat start: Character! You gotta get me out of here!
Once freed: These things took out my squad. You want my help, you got it.
Information
Crab Spiders function much like SWAT teams in other cities, and are dispatched to deal with high-level threaths like super-types. They're equiped with full body armor, larger weapons and a set of mechanical spider arms that turn them into death-dealing machines.
Powers
Powers
Channelgun Ranged, Moderate DMG(Energy), Foe -DEF
Your backpack has a built in energy Longfang Channelgun which fires bolts of energy.
Suppression Ranged (Cone), Moderate DoT(Energy), Foe -DEF
Your Longfang Channelgun may also fire long bursts of energy, causing moderate damage in an large cone in front of you.
Slice Melee, Moderate DMG(Lethal), Foe -DEF
The arms of your backpack may be used to slice at opponents for moderate lethal damage, as well as reducing their defense.
Arm Lash Melee (Cone), High DMG(Lethal), Foe -DEF
The Crab Spider's backpack is capable of making rapid attacks with its many arms dealing heavy damage to foes within a short cone in front of the user.
Wide Area Web Grenade Ranged (Targeted AoE), Foe Immobilize, -Fly, -Recharge, -SPD, -Jump
You have been caught in a web. You cannot move or fly and your attack speed is reduced.
Venom Grenade (Only Level 40 and up) Ranged (Targeted AoE), Moderate DoT(Toxic), Foe -Resist(All)
This poisonous grenade causes toxic damage over time and weakens the resistance of all foes within the area of effect.
Fortification (Only Level 40 and up) Toggle: Self +Res( S10 L10 F20 C20 E20 N20 T20 ), Prot( Ho 4.152 Im 4.152 St 4.152 Sl 4.152 ), Res( Sl 50% )
Your Crab Spider Armor Upgrade improves your protection to Smashing, Lethal and Psionic damage types, as well as increasing your protection against most status effects, including Confuse, Fear, Disorient, Hold, Sleep and Immobilize effects.
Crab Spider Armor Auto: Self +Res( S30 L30 P20 ), Prot( Ho 4.0 Im 4.0 St 4.0 Sl 4.0 Co 4.0 Fr 4.0 ), Res( Sl 50% )
Your Crab Spider Armor Upgrade improves your protection to Smashing, Lethal and Psionic damage types, as well as increasing your protection against most status effects, including Confuse, Fear, Disorient, Hold, Sleep and Immobilize effects.