gastroparasitus

gas·tro·par·a·si·tus

(gas'trō-par'ă-sī'tŭs),
Unequal conjoined twins in which the incomplete parasite is attached to, or within, the abdomen of the autosite. See: conjoined twins.

gastropagus parasiticus

Unequal conjoined twins in which the parasitic twin is attached at the abdomen.