Evil Meru (邪悪なメール Jaaku na Mēru) is a song first featured in Keroro Gunso the Super Movie 2: The Deep Sea Princess de arimasu!. Later this song becomes the anime soundtrack of the Season 4.
Keroro Ost Movie 1 2 3!-20-Jaaku na Meeru
Background[]
It was first heard when Meru (humanoid form) is placing Natsumi on his body as he blames Maru not to let anyone to enter the castle. And it was heard again when Meru grow even larger, becoming a ferocious monster to conquer by turning the underwater into his planet.