I like to shower at night mainly because I'm too cold and tired in the morning :S i think it feels miserable to shower in the morning
I like the idea of going to bed all clean and nice. it's also really relaxing so it helps me wind down from the day
Slaughtershy only showers when there's a full moon - very very smelly
He seems to be mistaken, Karla doesn't bathe at all.
That being said, I much prefer to shower at night. I feel disgusting going to bed all dirty >w< I honestly can't sleep without a shower.