
If the Sole Survivor chooses the blow up the Institute, not only Wanamingos, but Mutant Wanamingos roam across the wasteland and can be found with random encounters.

The Sole Survivor can find a holotape detailing the origin of the DNA and the scientific data about them, most of the lab is blocked an unaccessible, but one of the parts the Sole Survior can access reveal a tunnel to the outside, too small for an adult, but large enough too allow these creatures to escape. (Time: Present Fallout 4) Hidden in a forbidden section deep inside the Institute (due to uncontrolled speciments) are hundreds of Wanamingos. One of them decides that this team isn't good enough and contacts with a connection he has with the Institute.

He collects the remains and decided to start his research with a small group of scientists. He decided that if he can find a way to make more and put some kind of control on them, they would prove really good weapons. (Time: Year 2244) A post-war scientist found the remains of the last breedable female Wanamingo after the Chosen One killed her.
