Not really happy with the names, especially with Rerir since that's a mythological figure [picked it out of a hat this time].
Pasim exoskeletons and Rerir battlesuits are optimized for amphibious ops; their distinguishing feature is the "prawn drive," a series of paddles that operate in the same fashion as those found in aquatic crustaceans.
Pasim exoskeletons are notable for their arm configuration; in addition to the usual "hands" they have two backwards facing manipulators [used for reloading and removing piggybacked stuff] and a pair of thigh mounted retractable support claws.
Rerir suits are somewhat more conventional, although the "croc's" distinctive snout has led to a few derogatory monkiers such as "furry" and "duckie" amongst its operators.
[Rerir preliminary sketches]