Ovid, Metamorphoses

Daphne, fleeing Apollo, becomes a tree:

"Her prayer was scarcely finished when she feels / a torpor take possession of her limbs -- / her supple trunk is girdled with a thin / layer of fine bark over her smooth skin; / her hair turns into foliage, her arms / grow into branches, sluggish roots adhere / to feet that were so recently so swift, / her head becomes the summit of a tree; / all that remains of her is a warm glow." (I.754-762)

Io, turned into a cow, can't speak, so she writes:

"when she tried to utter a complaint / she only mooed -- a sound which terrified her, / fearful as she now was of her own voice" (I.883-5); "If words would just have come, she would have spoken, / telling them who she was, how this had happened, / and begging their assistance in her case; / but with her hoof, she drew lines in the dust, / and letters of the words she could not speak / told the sad story of her transformation" (I.896-901)