What is a trait or skill in the animal kingdom that is achieved in two different ways by two different animals? Besides the trait of animal intelligence.
Probably the two most important traits or skills in the animal kingdom are 1) getting food and 2) reproducing. If animals fail at either, of course, it's the end of the line for them. Because these two factors are so central to the lives of animals, I think you might be interested in focusing on either or both.
All animals must succeed in producing the next generation, for example, but they do it in very different ways. Even those animals that rely on sexual reproduction can use very different strategies. Fertilization can occur inside or outside the animal's body, the eggs can be stored inside or outside the body, the offspring can be abandoned or guarded, etc. Some animals bear only one offspring at a time, while others generate dozens or perhaps even hundreds.
The diversity is amazing. Frogs may seem to be one type of animal to us, for example, but some lay their eggs in water, others in wet clumps in trees. Some abandon their young from the start, but others guard the eggs and even the tadpoles.
If you can't compare frog to frog (of different frog species), because they might not qualify as "two different animals," you could compare one type of frogs to humans. Or you could be even a little more creative in your comparisons, such as comparing how a web-weaving spider catches food to how a human trapper might do the same.
Two very different animals are the elephant and the cat. They share the aesthetic skills of being able to and enjoying painting. Much has appeared in recent decades on the aesthetic of cats who paint and more is appearing on the aesthetic of elephants who paint. these two types of animals approach painting with differing methods. Elephants use their most versatile appendage for creating paintings; that is they paint with their trunks. Cats also use their most versatile appendages, which in their case is their front paws. Elephants have traditionally used their trunks to do work, such as carrying logs, in Asia. Cats instinctively use their paws for hunting, nurturing kittens, playing and some even pick up pits of food with their front paws. Since elephants use their trunks the paint strokes are wide and slow. On the other hand, since cats use their front paws while standing on their back feet (usually), their strokes are not only small, they are also quick.