When Hiccup, Astrid, and the other Dragon Riders of Berk came to rescue Stormfly, they found Dammen showing off the egg, along with a Timberjack and Boneknapper whom he hadcaptured. When Toothless blasted fire at the Northlanders, he freed the Timberjack and Boneknapper, and one of his fireballs incubated the egg, causing it to hatch into a baby Whispering Death.
Despite knowing the dangers of its species, Hiccup decided to try to train it. Fortunately, he was successful and the baby Whispering Death returned to Berk after Dammen had been defeated. He was last seen sleeping comfortably on Stormfly with the other baby dragons rescued from Dammen.
The Whispering Death's egg.
Baby Whispering Death attack.
Baby Whispering Death free.
Hiccup trying to train the Whispering Death.
Baby Whispering Death trained.
The Whispering Death with Stormfly and the other babies.