The House of Arden by Edith Nesbit

And it was -- it was the living image of the little pig-like animal that was stamped in gold above the chequered shield on the cover of the white book in which they had found the spell. And as on the yellowy white of the vellum book-cover, so here on the thymy grass of the knoll it shone golden. The children stood perfectly still. They were afraid to move lest they should scare away this little creature which, though golden, was alive and moved about at their feet, turning a restless nose to right and left.

"It is," said Elfrida again, very softly, so as not to frighten it.