The Killer is the BBot Attacker, this is the attacking feature of the BBot. It can run from monsters, keep you out of the waves path, execute macros, cast spells, use runes and some other things. Furthermore, the Killer auto-synchronize normal attacks with spell attacks, like runes.

Self-Defense Attack: the BBot will attack creatures only when you are attacked by them.

Attack All (Based on Killer List): it reads all the information on the Killer list.

Max Distance: is the max distance, in SQMs, that the BBot will keep the target tracked, by default it is 9 (covers all the Tibia screen's tiles).

Never attack players: the Killer can attack players when they attack you, but when this option is checked the bot will ignore all players that are attacking your char.

Shootable Check: this setting makes the BBot check if the target is shootable (like if you can shoot a rune on the monster), this way the BBot does not attack monsters on the other side of walls. By default this option is checked/enabled and is reccomended to be as it is.

[ Chase Target ]: this button show some instructions on how to keep chasing the target using the Tibia client. It's a good idea to read these instructions.