Level 25 Slayer is needed to kill the Cockatrice. If you are assigned Cockatrices as your slayer task, killing a cockatrice will provide you with 19.5 Slayer XP.
Charm Drop Rates
A Mirror Shield
is needed to defeat the Cockatrice, without it you risk suffering high damage, and a major decrease in all combat skills.
The winged reptile.
Clue scroll (level-2), Starved ancient effigy, Cockatrice head
Bones (100%), Coins, Iron boots, Limpwurt root, Law rune (2), Water rune (2), Nature rune (2-6), Potato seed (4), Steel longsword, Iron sword, Steel dagger, Onion seed (4), Tomato seed (3), Watermelon seed (2), Cabbage seed (4), Grimy herbs, Fire rune (4-7), Sweetcorn seed (3), Chaos talisman, Iron javelin (5), Rune javelin (5), Cockatrice egg, White mystic boots, Green charm, Gold charm, Crimson charm, Blue charm, Cockatrice skin