You can create your own boot animation for your device. The Android platform provides an easy way to replace its default boot animation by putting a bootanimation.zip file into /system/media/.
To create your own bootanimation.zip file, see How To Change, Customize, and Create Android Boot Animation
How to install the boot animation:
On the host, use the ADB to download the bootanimation.zip file into the device.
$ adb push ~/Downloads/bootanimation.zip /mnt/sdcard
On the device, remount the /system to writable, and copy the file:
$ mount -o remount -w /system
$ busybox cp /mnt/sdcard/bootanimation.zip /system/media/
$ mount -o remount -r /system