Never mind a text character crashing your phone — if you’re on Android, your choice of wallpaper could be a larger problem. Users have discovered (via Android Authority and 9to5Google) that an innocuous landscape photo is “soft-bricking” some Android phones when it’s used as a background. Your phone isn’t completely dead if it happens, but it’ll get stuck in a loop that turn the lock screen on and off, even after a reboot. Your recourses are to either use safe mode to delete the photo file or use the bootloader to reset the device entirely.
The issue may come down to the color spaces your phone supports and how they’re handled. Dylan Roussel from 9to5 discovered that the source image uses the RGB color space instead of Android’s preferred sRGB, and Android 10 doesn’t convert it where the Android 11 preview does — that causes problems any time an incompatible phone has to display the picture, which is a problem if you’ve just set the photo as your wallpaper. Other images will likely lead to the same issue.