chimera
noun
chi·me·ra
| \ kī-ˈmir-ə
, kÉ™-\
, kÉ™-\
Definition of chimera
1a
capitalized
: a fire-breathing she-monster in Greek mythology having a lion's head, a goat's body, and a serpent's tail
b
: an imaginary monster compounded of incongruous parts
2
: an illusion or fabrication of the mind
especially
: an unrealizable dream
a fancy, a chimera in my brain, troubles me in my prayer — John Donne His utopia was a chimera.
3
: an individual, organ, or part consisting of tissues of diverse genetic constitution
A hybrid created through fusion of a sperm and an egg from different species is a chimera.