The aye-aye (Daubentonia madagascariensis) is a lemur, a strepsirrhine primate native to Madagascar that combines rodent-like teeth that perpetually grow and a special thin middle finger.From an ecological point of view the aye-aye fills the niche of a woodpecker, as it is capable of penetrating wood to extract the invertebrates within .(source)
A large stork-like bird, the Shoebill lives in large swamps in Eastern Africa and can grow to more than 1.5 m (5 ft) tall and can have a wingspan of up to 3 m (10 ft). Recognizable by its enormous bill and terrifying gaze, these predatory birds prey on fish, frogs, and reptiles such as baby crocodiles, insects, and even small mammals.
Grimpoteuthis, also called Dumbo Octopus, is a genus of pelagic umbrella octopus that live in the deep sea. Prominent ear-like fins protrude from the mantle just above their lateral eyes.(source)
Humpback Anglerfish is one of the scariest animals in the world, and is a deep sea creature that inhabits all oceans of the world. Found at depths of at least 2 km (6600 ft), the fish lives its life in the complete absence of sunlight. Like all anglerfishes, this specie is also luminous to attract prey. Despite its scary appearance, the fish is just a few centimeters long.