An unnamed "super-weapon" was commissioned by the Galactic Empire, sometime around the Battle of Yavin, for development on Kamino.
The creatures developed by the project were at least 6 meters tall, with thick, blaster-proof skin, that had six strong tentacles to move on, with jagged teeth along it's mouth, had a poisonous sting, and were capable of rapid movement both on land and in water. Furthermore, the creatures were designed by the Kaminoans to be capable of transporting prisoners via an air-tight pouch in its stomach.
During Red Squadron's mission to Kamino, one of these creatures swallowed both Luke Skywalker and Lune Oddo Divinian whole, transporting them to an underwater cave which served as the creatures' lair. Either this creature, or one of its identical brethren, met its match when Divinian dispatched it with Skywalker's lightsaber. Skywalker and Divinian then used its air-tight stomach to attempt to swim to the surface. But were then surrounded by the bretheren of the beast before being saved by Han, Chewbacca, and R2-D2.
During Red Squadron's escape from Kamino, twenty or so of these creatures disabled multiple Imperial aquatic tanks, dragging them down into Kamino's depths.