If you have a warm-blooded, furry, 4-legged or 4-finned animal, and it has offspring, you would have to observe it nursing those offspring to confirm that it was a mammal. There are other clues, such as the cervical vertebrae (which number 7, except for the dugong which has 6), the arrangement of the skull, and the connection of bones in the inner ear. But these can usually only be identified from skeletal remains.
Magpies, which are members of the crow and raven family, are the only non-mammal animals that are intelligent enough to recognize themselves in a mirror.
The African giraffe would be the tallest mammal.
You would recognize a mosque because it has a round thing on the top.
The state mammal of Texas is the armadillo.
No it isn't. If it was a mammal it would have live babies and breastfeed its young, but a flatworm lays eggs.
While the basilisk is a fictitious creature, it is not a mammal, it would be a reptilian creature, since it is a snake.
Animalia
yes
Nails would be split
By the character of their conduct. How would you recognize a Christian or a Zoroastrian? There are no physical characteristics by which to identify a peson's religion, but there are ways to recognize whether someone lives according to the teachings of their Faith.
A Blue Whale is the largest mammal on earth and I would imagine at 16,000 lbs at birth the baby Blue Whale the largest baby mammal on earth.
That would be considered the human.