Board Thread:General Discussion/@comment-24922135-20170327002924/@comment-24922135-20170327115228

Ventrillosquid was also a concept never put into the show though. Derrick just decided to throw him into that episode because someone asked about the aliens Ben used.

Strictly speaking, since Thriller Whale was actually mentioned in an official CN channel and not just on some forums, Thriller Whale is more legit than Ventrillosquid.