Archelus (アーケルス, Ākerusu), alternatively romanized as Archeluth, is a new kaiju-type enemy introduced in Earth Defense Force 5.
Archelus is a heavily-armored kaiju enemy encountered throughout Earth Defense Force 5. While it is slightly shorter than the 72 meter-tall Erginus at 69 meters, it is considerably tougher and harder to kill. Archelus attacks by performing a bodyslam, curling into a ball and rolling around the area, and launching exploding rock-like structures on fire from its back. Archelus first appears on a mission where the EDF confronts and kills an Erginus using its EMC tanks. Suddenly, Archelus rushes into the stage and attacks the EDF forces, proving resistant to the EMCs' lasers which had slain Erginus. Archelus reappears throughout the game as an unkillable enemy, which will at times appear on stages after the player has killed a set number of smaller enemies. Archelus cannot be killed in battle until later in the game due to its instant recovery capability, after the EDF has recovered a gigantic mech known as the Gigantic Unloader Barga and brought it to a factory area. The Barga confronts Archelus on this stage and successfully kills it. However, numerous Archeluses appear on a stage late in the game after a battle between several Bargas and an army of Cosmonauts and Erginuses. They will attack the surviving Bargas and EDF soldiers, but more Bargas will be dropped into the stage for the player(s) to commandeer. These Archeluses can then all be defeated using the Bargas.
- Like Erginus, Archelus' role in Earth Defense Force 5 is a reference to the frequent trope of alien invaders utilizing kaiju to attack human civilization in science-fiction. The use of the Gigantic Unloader Barga to battle both Erginus and Archelus recalls the trope of utilizing giant mechas to battle giant monsters, as seen in films like Godzilla vs. Mechagodzilla II and Pacific Rim. The Barga and its predecessor Walking Fortress Balam specifically resemble the Jaegers from Pacific Rim.
- Archelus' appearance and abilities, specifically its rounded spiky carapace and ability to curl into a ball and roll as an attack, are clear references to the monster Anguirus from the Godzilla series. Its status as an ally to the Godzilla-inspired Erginus reflects Anguirus being a frequent ally to Godzilla. Its large hands that it uses in combat and the projectile weapon on its back are similar to the Kaiju Leatherback from Pacific Rim, which like Archelus was deployed into battle alongside another Kaiju, Otachi.
- In addition to Ankylosaurus and Archelon, other extinct creatures such as Saichania and Sauropelta may have inspired Archelus' design.