using the create variables library do what the title says
the behavior is mostly expected but the sprite local variable doesn't appear in the block palette, the one that looks global is actually the local one.
the sprite variable takes precedence over the global one which makes sense, the delete variable block deletes only the sprite local variable
might be useful for reporter magic and metaprogramming
if this were to become a proper feature i would recommend allowing it from the variable create button, showing the local variable, and greying out the global version in the palette