The 27-year-old actor was completely unrecognizable dressed as Ursula the Sea Witch from The Little Mermaid. The intricate costume featured lots of white makeup, an epic sky-high wig and an ample bosom.
Haynes even staged an Ursula nip slip. "Poor unfortunate souls," he Instagrammed, quoting The Little Mermaid villain.
The actor also revealed what the sea witch would look like eating carbohydrates. "Ursula loves diners," he wrote to his 2.9 million Instagram followers. "Ursula loves her fans."
After the night was over, Haynes Instagrammed the removal of his costume and quoted Beyonce. "I woke up like this," he captioned the video.
Haynes was able to one-up his 2014 costume, which was also pretty epic. The CW star caused jaws to drop last Halloween when he stepped out dressed as Princess Fiona from Shrek.
Nick Jonas also went all out with his Hamburglar costume. Check it out: