Make sure you've edited the monster ID range inside /src/map/mob.h -- if you're using an older version of rAthena (latest trunk has a sufficient ID range for the mob #ID you're attempting to use).
#define MAX_MOB_DB 5000 in file, https://rathena.svn.sourceforge.net/svnroot/rathena/trunk/src/map/mob.h -- If you need to increase this number, be sure to recompile and reboot your server, as it's a change to the source.
If you haven't already, @reloadmobdb, and make sure your lua files now match the updated #ID for your Hellbat monster.
You don't show where your sprite/act are located in your screenshots. Make sure they're located in data/sprite/¸ó½ºÅÍ/ -- If they're not already there, move them there/make a new folder at that path and place them there.