"Little" MO
New Zealand Mudsnail
Gerard "the Pincher" Green Crab
Zeke "the Prowler" Zebra Mussel
Knotty
"the Monopolizer" Japanese Knotweed
Nick "the Gnasher" Nutria
Morty "the Menace" Chinese Mitten Crab
Kira "the Killer"
Green Algae
Clyde "the Smacker" Silver Carp
Carrie "the Creeper" Cordgrass
Drusilla
"the Strangler"
Hydrilla

Hydrilla

SGNIS Images of Hydrilla

http://www.dpiw.tas.gov.au/inter.nsf/WebPages/SLEN-5NKA8S?open

http://www.massnrc.org/pests/pestFAQsheets/hydrilla.html

http://en.wikipedia.org/wiki/Hydrilla