Double Attack and Speed significantly when either Berserk, Infatuation, Lure or Wither status effect is cast on them.
The Nympheus is a Insect/Odonago-type monster in the School Fare series. They are generally agrressive, and a hardy chaser. Nympheus resembles a giant dragonfly nymph, with rather caterpillar-like large abdomen.
The Nympheus is directly based on "Nymph", a type of stage that is practically similar to the larval stage in insects. Nymphs are however, does not undergoes metamorphosis into their imago/adult stage via pupal/cocoon stage, but only sheds their skin like how grasshoppers does.
Nymphs are very similar to their adult form, most of them may undergo adult stage earlier, if they have already reached sexual maturity.