### Instruction: How many arms does Hapalochlaena lunulata have?
### Input: The greater blue-ringed octopus (Hapalochlaena lunulata) is one of four species of extremely venomous blue-ringed octopuses belonging to the family Octopodidae. This particular species of blue-ringed octopus is known as one of the most toxic marine animals in the world.
### Response: Hapalochlaena lunulata is an octopus, so it must have eight arms.