People didn't have the science we have today so they made up things and stories to explain things.
I believe so
unicorns, fire breathing dragons, phoenix, griffins, mermaids, and on and on.
If mermaids existed a common depiction shows them with hair and with breasts so they are mammals which, by default, would make them animals as well since mammals are animals.
Gingersnap is a common Moshling on Moshi Monsters.
Yes, Fifi is a common moshling.
No. Cutie Pie is an Ultra-Rare moshling on Moshi Monsters.
Fifi is a Common moshling.
Whatever isn't a factor of 120.
Although it's not mormally said that way, it would be "quince cientos." I believe it would be more common to say "mil quinientos."
They have scailes finlike ears and the lay eggs.
Most artwork depicting mermaids show them to have breasts. This would lead to the conclusion that without a doubt mermaids are mammals and therefore nurse their offspring. Generally it seems that they are modest about showing their breasts and wear a brassier of sorts made of seashells. While I would think that this would be very uncomfortable, this does appear to be their common practice. So just as dolphins and humans are mammals and the females of these species produce milk for their young, mermaids would do the same for their children.
wolves and monsters under the bed