Why I add birds to the reptiles category, is because they say that they descended from dinosaurs, which they are reptiles, which also makes birds reptiles as well, even when they also say that crocodiles and turtles are their closest relatives
Actually birds don't have fur, they are covered in feathers, just like some non avian dinosaurs that have feathers, known as theropod dinosaurs, like raptors for example, even when their feet and legs have scales like reptiles, and yes it is proven that birds are indeed reptiles because of the evolutionary line.
and I have to say, birds can be reptiles in real-life, but in the game the birds category and reptiles categories are quite distinct, so I think it would be better if they steyed separeted, since this reflects better the gameplay.
In the game Saber Toothed Tiger is the file name for the object.
There are some ways to see if the real name of the object in-game. In scribblenauts unlimited you can create the object, restart the game and edit the object, the name in the Source Object will be replaced by the object name.
Or more easily you can create an object in the object editor, go in the Scripting tab and make the object "Create an Object", when you close and open the object editor again you will get the true name of the object.