pick a niche. really search your soul, think about what you'd be good at, okay?
basic producer (usually grasses, algaes, weeds, and other low plants)
grazing herd animal (sheep, deer, triceratops)
scavenger or carrion-eater (maggots, raccoons, vultures)
large habitat-providers (trees, cactus, kelp)
smallish predator (bats, frogs, spiders)
larger predator (wolves, cats, snakes, hawks)
largest predators (bears, crocodilians, sharks)
small herbivores (mice, songbirds, insects)
decomposers (fungus, isopods, a lotta arthropods)
intelligent tool-user (humans, chimpanzees, octopus, corvids)