Yes, you can easily create a bootloop or prevent your device from properly booting if you make the wrong changes in the boot animation. So we need to know what you did to help understand what caused the phone to soft-brick.
The easiest way to recover from a soft-brick caused by mucking with the boot animation is to backup your phone using your custom recovery BEFORE mucking with it, then flashing your backup immediately after you brick it! The harder way is to hope you still have access via fastboot and then replace the boot animation files you mucked with using the backups of the original files that you presumably saved.
Sent from my Nexus 7 using XDA Free mobile app