Primus River Creature

The Primus River Creatures are an unnamed aquatic species native to the planet Primus.

Biology
Though the creatures themselves haven't been entirely observed, their visible eyes and tentacles suggest that they could be alien cephalopods. They have blueish skin and dwell underwater.

History
During their visit to Primus, it briefly appeared while spying Ben, Kevin and Gwen before it grabbed Ben, pulling him into the river. Kevin want under to save him only for Gwen to use her powers.