My ice cube froze in this shape

water expands when it freezes. if there is a hole in the top layer of ice, cold water is forced through the hole and forms spikes of ice like this sometimes

I was told this

“There's a fan in the freezer that's blowing on the liquid water and making it crest. Like a little wave. And when it starts to freeze, it'll freeze a little higher and higher, building a reverse ice cycle.”