Giant Predatory Diving Beetle (Dytiscidae)
Giant diving beetles are predatory aquatic insects found within many seasonal wetlands, lakes, and slow-moving streams. Using their wide and hair-covered limbs for propulsion for chasing prey, they will carry a bubble of air with them that allows them to breathe while underwater.
The larvae, often referred to as "water tigers" are arguably even fiercer and more aggressive. Lying in wait by hovering within the water column, they will latch onto potential prey and inject digestive enzymes that literally liquify it.
Information source: https://uwm.edu/field-station/predace....