|First appearance||Movie 5|
|Voiced by||Shigeru Chiba (Japanese)|
|Species / Type||Evil Spirit|
Akuaku (アクアク)is the main antagonist of Keroro Gunso the Super Movie: Creation! Ultimate Keroro, Wonder Space-Time Island, de arimasu!!.
Akuaku is a peculiar, yet unique alien, his ability is shown that he can transform into a Keronian that resembles the host that he has eaten. Although Giroro and Dororo say he's a Keronian, he is not one of the Keronians's/Maronians's species.
He is afraid of water, although it won't kill him.
Akuaku is a small purple blob with only one eye and a large blue jagged mouth in his original form. Once he eats a Keronian, he turns into a Keronian similar to the one he ate except a more demonic-like appearance, purple stomach, and a yellow jagged collar. The symbol on his forehead is the same symbols of the Keronians he has eaten on top of a staff-like symbol. The symbol on his stomach however, resembles his eye in his original form.
Akuaku are evil spirits that love to play pranks. When a diver managed to take away a moai statue that was keeping him inside, he escaped. He managed to defeat Alisa and her father easily. After a tough battle with Keroro and his platoon, he manages to steal Kururu's knowlege, Tamama's power, Dororo's skills and Giroro's determination by swallowing them, absorbing their energy and then spitting them out. He doesn't attack when it's raining because he is afraid of water. When Keroro is transformed into Makemake, he is surprisingly beaten up by Keroro but comes back to take him down. As he was about to defeat Keroro, he is grabbed by him and purified by the spirits of the moai statues. However, he returns in a smaller blob form and is soon eaten by Alisa's father.
- Akuaku shares common similarities with Ketsubakuchiku, including the ability to shift into anything.
- Name is a Reference to The Crash Bandicoot Character: Aku-Aku but the crash bandicoot AkuAku Is Good, Not Evil.