Incubator

Opposite of "sperm donor", an incubator is a semi-sentient hominid that has unprotected sexual relations with its partner and serves as host for the resulting conception. 9 months later the incubator's job is finished and it really should be separated from the offspring and released back into the wild, but in many cases it develops a form of psychosis which causes it to have an unhealthy trauma-bond with the offspring and turn viciously on the baby's father, leading to actions which result in the incubator being rewarded for its disgusting actions and given "child support", better known as "incubator tax".