-Hostile

-Can be found in.. You guessed it! Caves! (You might have to go a little deeper in order to find them in 1.17+ versions)

-Preys on Cockroaches

-Can be quite hard to avoid

-Poisons you with their mandibles (I hope that answered your question about why the centipede doesn't look clear, i also drank my milk from the milk bucket)

-Drops their legs upon death

-Legs can be used to make the potion i talked about earlier

-Or you can use them to make some fancy leggings that gives you the ability to climb walls