Octo-ooze at level 5 may still seem weak, but with the size-10 Housing space, they can easily overwhelm Snipers, Bunkers, Teslas, even Drull if used in large numbers. Railguns can also kill octo-oozes as quickly as it could to pokeys, so be careful if you see any of them. It is recommended that you upgrade them to level 5 before approaching Lasers and Cannons. At higher levels, Octo-ooze can still be efficent, and can be used to take down exposed Aerial Defese Towers. And Octo-ooze can also be used to farm the Kozu tribe with the help of Fomor, D.A.V.E and Zafreeti.
Octo-ooze can be efficent in bunkers, as they can stall enemy monsters. They are a health conscious type of unit, so they might be able to stall Putty Project X's longer than pokeys do, but the con is they aren't as successful as pokeys when it comes to injuring .