"An effective creature that I use has great health, great attack(close combat and fair ranged), and great abilities. The head of a sperm whale and the rest of its body is of a gorilla. The only problem is it is a level 5 creature and costs 526 coal but,(I dont rember how much electricity it costs!!)has 800 something health. Well gotta run, check ya later!" - Knot Me!

"baboon and sperm whale (head and tail whale) or chimpanzee and spermwhale (same as babale) are the best. if unlocked all the animals, combine a moose with a lobster with the body of a lobster" - nik

"Combine a moose ( if u have the bonus creatures unlocker) with a cheetah or a panther. use the moose head and body and the cheetah's legs. u will have a high attack, high health, fairly high defense, and high speed unit. The only drawback is a average sight radius." - Huh

"combine a prayingmantis and a sperm whale ( all mantis but whale head) [THIS GAME ROCKS!" - whellie

"On (I think) Mission 4...maybe 5. The one where you're trying to get a helipad. Here's a good way to get rid of the base on the other side.

Once you've got that helipad, combine a chimpanzee with a crocodile. Use all the parts of the chimp, except the croc-tail if you want it to be amphibious. So, you've got a size-5 boulder-chucking chimp. Woohoo! Fly over to the bottom right of the map, build a creature chamber and a workshop. Produce about half-a-dozen Giant Chimps to guard that workshop. Take the rest, as many as you can, and storm the base. Keep producing them to send in more as they're killed. This mission gave me a run for my money until I realized you could build from the 'copter." - Mindskape

"Combine Sperm Whale with Gorrila ,when you combine it it will be a strongest creature. After you have combined make it's hit points in genetic emplifer then you will get its health 1035!!! or 1045!!! You will win easily when you make lots of these creatures and attack." - Nikhil