Desert cholla can be nice to look at, especially in the late afternoon sun. Back-lighting on their thorny needles can make them look like they are glowing.
But don't touch! Don't even brush lightly against them. The thorns and bits of cactus seem to almost "jump" onto the unwary hiker (hence the nickname, "jumping cholla"). The thorns are barbed at the end, painful, and very difficult to remove.