A phenocopy is a non-heritable, environmental phenotype that is analogous to a genotype-determined phenotype in another person.
To put it another way, the phenotype induced by environmental circumstances resembles the phenotype induced by a gene.
Vanessa butterflies are an example of phenocopy because their phenotypic changes depending on the temperature of the environment. Himalayan rabbits can also do phenocopy.
When grown in mild circumstances, Himalayan rabbits are white with black tails, noses, and ears, making them phenotypically distinct from genetically black rabbits.
When subjected to cold conditions, Himalayan rabbits develop black colouring in their coats, making them look like genetically black rabbits. The Himalayan rabbit has a genetically black phenotype as a result of this.