Final answer:
Vipera Evanesca is not a recognized spell in the Harry Potter universe or fantasy literature. It seems to be a fabricated term, possibly combining the Latin for 'viper' and 'to disappear,' suggesting a fictional spell to make a viper vanish.
Step-by-step explanation:
The term Vipera Evanesca appears to be a spell name from the realm of fantasy, particularly the type found in works such as the Harry Potter series by J.K. Rowling. In the context of those stories, untransfiguration would be the process of reversing a transfiguration spell - that is, turning an object or creature that has been transformed into something else back to its original form. However, the term Vipera Evanesca is not a recognized spell or term within the canon of the Harry Potter universe or known fantasy literature.
From a scholarly perspective, 'Vipera' could reffer to a genus of venomous vipers found in Europe and Asia, while 'Evanesca' could derive from the Latin word 'evanesco,' meaning 'to disappear or vanish'. Combining these terms in a literary or fantasy context might suggest a spell used to make a viper or similar creature disappear.