Other: Watching the growth of a Crested Bunny Ears cactus

My girlfriend at work once purchased a Crested Bunny Ears Cactus (Opuntia Microdasys) that's been sitting at her desk for about half a year now. She has a natural green thumb so she's been regularly watering the plant twice weekly out of instinct. I'm kinda envious because I've had potted plants on my desk as well but I can't seem to keep them alive very long.  My girlfriend's cactus (affectionately called Lulu) has been growing surprisingly fast. Below are pictures of her as she's been growing up:

Picture taken when Lulu first came and settled in the office in May 2018

When Lulu first came in the office like this, I had half-expected she'd stay the same size all throughout the course of our time in the office, or that she'd wither away (given my experiences with plants, and not knowing that my girlfriend knows well how to take care of them.)

After 3 months, Lulu began growing a tiny stub on her right ear at the beginning of August 2018

It's very small but there's no mistaking it that something was growing on Lulu's right ear. It grew quickly in August, as the tiny stub got longer and reached higher and higher.

Lulu's stub a week after it's first appearance, still in August 2018

After yet another week into August, Lulu's stub was a stub no longer.

Lulu's current state, this December 2018

I'd like to add that writing on the whiteboard behind Lulu became a bit tricky now that Lulu got so much bigger than when she first got to the office. Lulu's bite stings and the pain can last for days if you don't wash the inflicted area. It's not that her spines were poisonous; they're actually just very minute in size, almost as if they're tiny clumps of hair. They detach from the cactus when you come into contact with it. The spines cling to your skin like they're tiny splinters and it hurts when you touch them. Since there's way too many to pull out using tweezers, washing the area is the only option.

With all of that said, we love Lulu all the same. She's been growing nicely underneath the fluorescent light of the office and cool, office air conditioner air. Her positive disposition can always brighten up the day.