The word for 'skeleton' in Petronius' Satyricon is indeed larva.
Potantibus ergo nobis et accuratissime lautitias mirantibus larvam argenteam attulit servus sic aptatam, ut articuli eius vertebraeque luxatae in omnem partem flecterentur. Hanc cum super mensam semel iterumque abiecisset, et catenatio mobilis aliquot figuras exprimeret, Trimalchio adiecit:
Eheu nos miseros, quam totus homuncio nil est.
Sic erimus cuncti, postquam nos auferet Orcus.
Ergo vivamus, dum licet esse bene.
As we drank and admired each luxury in detail, a slave brought in a silver skeleton, made so that its limbs and spine could be moved and bent in every direction. He put it down once or twice on the table so that the supple joints showed several attitudes, and Trimalchio said appropriately: "Alas for us poor mortals, all that poor man is is nothing. So we shall all be, after the world below takes us away. Let us live then while it goes well with us." (trans. Heseltine)
Note that the word typically means "ghost" or even "goblin," as Lewis and Short define it:
a ghost, spectre: “larvae stimulant virum,” Plaut. Capt. 3, 4, 66: “amator qui me et uxorem ludificatust larva,” id. Cas. 3, 4, 2; id. Aul. 4, 4, 15: cum mortuis non nisi larvas luctari, Plin. praef. H. N. § 31. — As a term of reproach, hobgoblin, scarecrow: “etiam loquere larŭa?” Plaut. Merc. 5, 4, 20: “nam haec quidem edepol larvarum plenast,” possessed, id. Am. 2, 2, 145.—
However, here it has to mean skeleton, model skeleton even. He's describing a put together skeleton (made of silver) that can move. To mean "evil spirit" here wouldn't make any sense.