Fload a dit :

I decided to give one of my Cactus Map's a try on hardmode. I was doing great, putting balloons below me so they wouldn't pop, but then the boards lifted all the mice into the spikey cacti roof and they all died. D:

Fload a dit :

Cactus blocks are deadly blocks that will kill mice on contact and pop balls and balloons. They are different from lava, which causes mice to go flying and wrecks most shaman builds.

What would it be used for?

Cactus blocks would be used for bootcamps especially, but would also be useful for different shaman maps. Since mice die instantly, there's no chance the mouse would fly into a board and cause the boards to spaz out and fly around.

Having a roof made of cacti makes balloons a bad idea.