"Fear me, for I am descended from tigers!"
"That would be much more impressive if you weren't only as tall as my boots and as heavy as this bag." -- Anon Guest
People assume. It's in their nature. They also fail rather spectacularly at connecting certain dots. Dots like - there's a small, medium, and large version of every type of creature. It's just that many of them avoid the more common thoroughfares, or interaction with the greater realms.
However, there are statistical outliers who will make blips on every bell curve. Such as Rumtum Taigr, a member of the Tabaxi species, but not the one more commonly known. He has currently been caught rummaging through the wrong Wizard's travel chest.
He is also currently unable to fight because being held at arms' length by any Medium creature is an effective tactic against small ones. That, as well as failing an intimidation check.