Threat of the Kronoborgs

Bioengineered kronosaurs were developed to devour space jellies that bred in the oceans, hence their long thin teeth. 

Once they went rogue, they’d eat anything and everything. 

Depicted here is an enhanced cybernetic model from Cyndyne, with retractable articulated legs for terrestrial excursions, as some jellies liked to lay eggs in freshwater lakes and even ponds. 

After The Fall, kronoborgs were liable to have their CCU's (Cybernetic Control Unit) hijacked by desperate rogue thought-hubs, afraid their erstwhile masters were going to shut them down just for releasing a nuke or thousand.