Is there an animal that is both poisonous and venomous?

The platypus is the only venomous mammal in the world. However, it is not venomous in the same way that snakes and spiders are. Platypuses have a spur on each of their hind legs that can inject a venom that is very painful to humans and can even be fatal to small animals. However, the venom is not as strong as that of snakes and spiders and it is not typically used to kill prey. Instead, the platypus uses its venom to defend itself against predators.