Harpies only appear if your altitude is high enough. A sky island works nicely.
During the day, away from spawn (about 1/3 of map), on grass
Yes, it can rain in Terraria. Special rain-themed enemies may spawn during this time, like Umbrella Slime and Raincoat Zombies.
You can spawn them by downloading it off websites. But I would not do that, because most of the data in the spawn commands and such are viruses. So, it seems the easy way to do it at first, but it also can be very harmful for your computer.
You never actually 'sleep', all beds are for is to change your spawn point.
the eye of cthulu will spawn at night rarely and goblin armies will attack
no you will get a error sorryi got an Xp too it wont work
Is the server up? or is the owner asleep or somewere.
slimes spawn only on slime chunks
NPCs need to have an appropriate house to live in. This requires you to have a space closed off, made with at least 25 blocks, a background wall made with at least 32 blocks, a table, a chair, a door an it must be well lit. Otherwise, no NPC will spawn even if you meet the requirements.
Madonna of the Harpies was created in 1517.
Because harpies are made up creature resembling angels that shoot metal feathers at any trespassers of what the harpies are guarding... Why would yu want harpies to be real they will kill you...
The Harpies were goddesses, and never destroyed being immortal and ageless.