"畸形的动植物" can be translated as "deformed animals and plants" or "malformed flora and fauna" in English.
"Deformed" emphasizes the abnormal shape or structure, which is a common and straightforward way to describe such phenomena.
"Malformed" carries a similar meaning but might sound slightly more technical or scientific.
"Flora and fauna" is a collective term for all the plant and animal life in a particular region or ecosystem, and using it here adds a touch of formality or scientific precision. However, if the context is more general or casual, "animals and plants" would suffice.
In most everyday contexts, "deformed animals and plants" would be the most appropriate and easily understood translation.