A few choice bits from the Cubivore instruction manual:

The more you mutate, the more popular you will be with females.

Raw-Meat will allow you to mate! Your offspring will be born with more meat flaps.

Press the A Button to BITE his Meat.

While biting, hold the control stick down to TEAR OFF his Meat.

When you eat a piece of Raw-Meat, you will then be able to enter a Love Tunnel. The females will drop by and it's mating time!

Females just love a male with "Experience"!

Your hump can be powered up by collecting Hump Bits and by using the Treadmill.

Use the Bullfrogstool to strengthen your tongue.

Z Button to take a doo.