Full Idea
If we analyze an ordinary physical object into matter, form and properties, the only item in the case of animate objects that has to stay the same as long as we can talk about the same thing is, on his account, the form.
Gist of Idea
For animate things, only the form, not the matter or properties, must persist through change
Source
report of Aristotle (Metaphysics [c.324 BCE], change) by Michael Frede - Substance in Aristotle's 'Metaphysics' p.76
Book Reference
Frede,Michael: 'Essays in Ancient Philosophy' [University of Minnesota 1987], p.76
A Reaction
I would have thought that might work for inanimate natural things, and for artefacts, to a considerable extent. The Ship of Theseus retains its form.