The flora and fauna of Catachan include the famous Catachan Devil, a voracious predator, looking somewhat like a scorpion. They can be up to 40 paces long but its weakness is in its bulk, it is slow moving and escape is possible.
The brainleaf, a vegetative carnivore, can attach its tendrils to the spine and brain of a person, taking over control of their body.
Grox, domesticated for pack and food on other planets, are wild here and are deadly predators. They are most famous for the galaxy spanning food consortium producing 'Grox Burgers'.
The spiker, another deadly plant, fires its spikes into people's bodies, which then sends out a mutation chemical which literally turns the person into another spiker.
The mantrap (a close but highly enlarged relative to the venus flytrap) is able to move towards its prey and actively swallow them.
Finally, there are many serpents on Catachan, including the Flying Swamp Mamba, the Coiling Death Cobra and the Catachan Black Viper, are all deadly to most beings. Some can kill in under 30 heartbeats.