The kappa is an ancient Japanese yokai.
In ancient times, this pond was known as "WaniKani Pond."
The toilet is a wonderful invention that has been handed down since ancient times to the present-day.
If you come to the party wearing something really, really old, everyone will know you're from ancient times (as if your wrinkles didn't give it away already, right?).
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.