The point in the 显示 is that a moose isn't really that scary, but Zim convinces Dib that it is. Its just meant to be funny because people aren't normally scared of a moose.
Not to sound like a nerd, but in real life, moose are actually really dangerous and have killed people, so we should really be scared of moose.
I think I remember something that because the moose was eating the walnuts, then that meant that it would eat the children and kill them. o.O I read that somewhere, just don't remember where....
