This bacterium sucks the life juices (cytoplasm) out of another bacterium called Chromatium. Don't worry, it won't attack you.
An example of a microbe that attacks another microbe is the bacterium Bdellovibrio. This bacterium attacks other bacteria, such as Escherichia coli (E. coli).
Some bizarre fungi can strangle worms called Nematodes. These fungi capture the worms for food. These fungi make ring-like nooses from their hyphae to capture the worms. Once the nematode is trapped, the fungus penetrates it, eating it.