Jasper Gigas is the boss in stage 3-A (1995 Chechnya)
Anticipating that their munitions factories in 1995 would be detected by ATHENA, BRES sent a pair of siege tanks there to stave off attack. Where Staubteufel is designed expressly to attack aerial threats, Jasper Gigas is designed with artillery attacks in mind, although it's still no slouch against airborne foes. Before engaging the Anemoi, it will first try to destroy the ATHENA reconnaissance installations. If even one is destroyed, the analysis of the creation of Orion's Arrow will falter, preventing ATHENA from detecting the threat at 2035 Iceland before the Stymphalian Birds attack Lisbon.
"Gigas" is the singular of "Gigantes" (Hellenic for "Earth-born"), a race of mighty humans with serpents' bodies for legs. Gaia bore them through Tartaros as one of her attempts to cast down Zeus and free the Titanes from their imprisonment. However, with Herakles's assistance, the Theoi were able to imprison the Gigantes under various mountains and islands. It was at that point that Gaia finally decided to deploy Typhon.