From Nookipedia, the Animal Crossing wiki
"I caught a spiny lobster! Who would give lobsters SPINES?" –New Leaf
Donating to the museum
In New Leaf
After donating the Spiny Lobster to the museum, the player can see it in the huge tank in the first room. The aquarium gives this description.
"The representative species for all large lobsters, they've become a lasting symbol of longevity. They live between rocks in shallow waters with octopuses as their natural enemies. Only octopuses are capable of reaching in between the rocks with their long arms to catch them."