Dash brought Shoggoth (per my suggestion), because he has soooo many teeth (36, in fact) and the dentist might want to look at them, too. I'm such a geek!
Dash told the dentist, "Shagga' is a sea monster! He's a Kraken! He's very scary!" (note: we've told Dash Shoggoth is a Kraken [as seen in Fellowship of the Ring] because that's easier to understand than protoplasmic hell-creature created by the Elder-Things)
The hygenist asked, "Oh, should I be afraid?"
Dash said, "No, he's only a toy."
The dentist asked, "He has so many eyes, too, does he watch over you?"
Dash said, "Yes, he keeps my nightmares away!"
Background on Shoggoth (originally from a tale by H.P. Lovecraft), according to Wikipedia:
"The shoggoths were created by the Elder Things as living bioengineered construction equipment. Being amorphous, they could take on any shape needed, making them very versatile within their aquatic environment. Though able to "understand" the Elder Things' language, they had no real consciousness and were controlled through hypnotic suggestion.
The shoggoths built the underwater cities of their masters. Over millions of years of existence, some shoggoths mutated and gained independent minds. Some time after this, they rebelled. Eventually, the Elder Things succeeded in quelling the insurrection, but thereafter watched them more carefully. By this point, exterminating them was not an option as the Elder Things were fully dependent on them for labor and could not replace them. It was during this time that, despite their masters' wishes, they demonstrated an ability to survive on land.
Within the Mythos, the existence of the shoggoths possibly led to the accidental creation of Ubbo-Sathla, a god-like entity supposedly responsible for the origin of all life on Earth, though At The Mountains of Madness brings up the possibility of the Elder Things being the creators, having made early life as discarded experiments in bioengineering."
Shoggoth, being a nightmare creature himself, must know the scene pretty well; I'm glad he's on Dash's side in the nightmare business. Woot to healthy teeth!