Lepus is a large rabbit boss exclusive to the Mobile version of Terraria. It can be summoned with the Suspicious Looking Egg, which is dropped by Diseaster Bunnies during the Easter season. When summoned, the message "Lepus has awoken!" will display. Lepus can be spawned at any time of day.
Lepus lays two types of Easter Eggs: small ones that hatch Diseaster Bunnies, and bigger ones that hatch another weaker Lepus. These eggs can be damaged and destroyed by the player before hatching. A maximum of 5 Lepus can be spawned from the large eggs laid by the original Lepus, and after there are five, no more large eggs will be laid. Only the last remaining Lepus will drop items.
If you defeat Lepus while an unhatched large egg is still present, it will spawn around 3-6 Diseaster Bunnies instead of a new Lepus.
Since it drops its own spawn item it is easier to farm then most bosses.
Tips
Lepus can be trapped easily, since it can't fit through small gaps, but its smaller Diseaster Bunnies can still reach you.
Like most seasonal content, Lepus can be fought by changing the device's date to a day in April, when Easter is set to occur. Not all devices will allow the date to be changed, however.
Trivia
Lepus has an unused animation: instead of standing before making an egg, it would close its eyes and fold its ears, then open its eyes and mouth, and lift its ears up.
The word "Lepus" means "hare" in Latin, and is used today as the name of the genus that hares and jackrabbits belong to. Rabbits, known alternately as "bunnies" and associated with Easter, are not actually members of Lepus.