Swamp Thing, Vol. 2 #81

Invasion - Widow's Weed
Invasion Extra!: First Strike! Swamp Thing disappears, leaving Abby alone and pregnant in the swamp...and facing forces from the alien invasion. Written and pencilled by Rick Veitch, and inked by Alfredo Alcala. Cover by Veitch. Cover price $1.25.
Release Date: 1988