Yes, many mammals are a threat . Predatory mammals like wolves, tigers, leopards and bears are very threatening to other animals that trespass on their territory.
Cats and Foxes
We found out it was not humane to threat anybody like that. Officially at least.
Communists and anybody who supported them.
loss of habitat
Well it does not really pose a threat although if you see it it might frighten you but there have been no reports of the monster destroying or killing anybody thus, it does not pose a threat and also HE IS REAL!!!
The tuatara is at threat from a number of introduced mammals. Rats are the main threat as they steal the eggs and also eat hatchlings. Cats and dogs will easily kill adult tuataras.
The European fox is introduced. Most Australian mammals are marsupials and the fox is an introduced placental mammals which is a considerable threat to Australia's native wildlife.
Well... birds, fish, mostly smal mammals but we can be a threat wiht bug sprays and stuff.
Leopards are carnivores who often eat small to medium sized mammals. Humans are the leopards greatest threat.
Larger mammals in the food chain that prey upon them; change in their natural habitat that deprives them of resources like food; extreme weather conditions for which they're ill prepared. The major threat that keeps mammals from surviving has always been the predator known as man.
Elephants are mammals. They drink their mothers milk from underneath the mothers until they are big. :)
The wizarding world was at war, everybody was under threat and anybody who fought in the final battle almost died.