You try your hardest to be an elf. You fail because you are already a kobold and being an elf is a horrible, horrible idea. Wait, what where you doing?
Oh yeah, sneaking into Cityshanks, the dwarven fortress.
Legend tells the artifact bronze dagger, Tributescar, is hidden deep in the vaults of Cityshanks. It's crafstdwarfship is of the highest quality. It's handle is studded with onyx and silver. On the dagger is an image of a dwarf striking down a dingo using Tributescar. Ever since you were a hatchling you knew, one day, Tributescar would be yours.
You have finally made it up this mountain to the front of the fortress. Now what do you do?
Convince the dwarves that you are a dwarf. It will be difficult, certainly, but it is what you have trained your whole life to do.
This is a wonderful idea! Why didn't you think of this sooner. You were going to wait for a goblin siege but that could take a very long time.
You try to be a dwarf and fail because you are a kobold. You wish you were as tall and broad as a dwarf. They have such wonderful beards and make such beautiful daggers. If you can make a disguise you are sure you will blend right in. You start by using your loin cloth as a fake beard.