If you think gestating one baby is tough, try 3,000. The squid Gonatus onyx carries around her brood of 2,000 to 3,000 eggs for up to nine months. The squid moms have their arms full: While carrying their eggs, they’re stuck swimming with their fins and mantle instead of their much more effective arms. 

So why would G. onyx take such care of its thousands of offspring? According to a 2005 study published in the journal Nature, the squid carry their eggs to deep water, where predators are rare. The deep-sea offspring are also larger and more capable of survival than shallow water squid.