The Scorpion in Parasite Eve II has received a very large downgrade from the scorpion in Parasite Eve. No longer an extremely dangerous monster, the Scorpion is about the size of a large dog and can poison Aya Brea with their stings.
Scorpions attack in packs (unlike their New York counterparts) which makes them easy to kill with area of effect abilities or weapons like the Shotgun or Combustion and Plasma. Automatic or Burst-firing weapons can also work on quickly taking Scorpions down one at a time, starting with the closer ones.
Once they melts, it will leave a poison puddle that can inflict damage and poison to Aya if she step on them. The puddle will be disappear after several seconds. If a Scorpion is killed via grenades or buckshot shot, their body will not leave a poison puddle.