The Retiarius is a giant spider added in Earth Defense Force 2025, first appearing in Mission 4: Setting Sun. It also makes an appearance in Earth Defense Force 4.1: The Shadow of New Despair. The Retiarius makes its home in huge sticky nets strung between buildings and cliffs. It is extremely dangerous: if you get stuck in its web you either have to destroy the web or the Retiarius lurking nearby. The creature makes a return in Earth Defense Force 5, but its name is changed to Aranea (アラネア, Aranea).
The Retiarius attacks by launching long web strings at a target: the number of webs launched at a time and damage potential of each string depends on the difficulty level. Once the target is ensnared, the Retiarius pulls them toward it with tremendous force, dealing passive damage to the target. If the target is pulled all the way to the Retiarius, it will launch its web attack at point blank range like a shotgun blast, dealing massive damage. If the Retiarius is standing on a Net, the target is dropped into it and immobilized.
Captured players must be extremely careful and free themselves as fast as possible, because more than one Retiarius can ensnare a single target, which can very easily drain all of the player's life away before they can hope to free themselves, especially on higher difficulty levels.
Use weapons with a fast rate of fire, as they can effectively stun-lock the Retiarius and prevent it from attacking.
Avoid using explosives, because if you get caught in the net, or if it drags you too close, you'll blow yourself up. Air Raiders should be especially careful if you're not in a vehicle, because limpet systems are next to useless when you're caught in a net due to their explosive nature, and the only other option is to wait for a friend to rescue you.
It's also worth noting that you cannot attack through the web, even while using explosives.
Keep an eye on the Retiarius. When it raises its front legs, it is casting its webs. If they are cast in your direction, you should dodge immediately.
Wing Divers should be careful not to fly into the nets. Their low armor rating can make the damage potential of the webs a credible threat: Make sure to bring a close range, high impact weapon to cut yourself out quickly before too much damage is done.
If you are caught in a line the Retiarius has cast, the line will flash red. Defeat the Retiarius connected to this line to escape.
- The Retiarius spider is most likely based on the Jorō Spider (Nephila clavata). This spider cannot throw its webs, though there are other spiders who can.
- There is a common glitch with the web: Retiarius' web can be shot over buildings, and if the player is caught, he may be pinned against the building. This attack can be difficult to dodge and is potentially deadly, because the player can't shoot through the building to attack the offending Retiarius. There is a chance that the player will be released from the web if caught in this unfair circumstance, but whether or not that happens is governed by time, health, and a hefty amount of luck. You can also destroy the building with explosives if you have any and easily solve this problem.
- Any building which a Retiarus web is attached to is programmed to be indestructible. This is most likely because if this were not done, there would be little point in having the web be able to take damage since most explosive weapons would destroy the building it was attached to in one shot.
- The Retiarius is named after a type of Gladiator who used weighted nets in battle. It means "Net-man" in Latin.
- In Earth Defense Force 5 the Retiarius is renamed "Aranea," which is the Latin word for "spider."