Cockatrice

You may mean Spirit cockatrice or Chocatrice.

Cockatrice are Slayer monsters that require level 25 slayer to kill. They frequently drop Limpwurt roots used in the Herblore skill. Players need to use a mirror shield when fighting these.

Locations

 * Fremennik Slayer Dungeon

Strengths and weaknesses
Players must use a mirror shield when fighting these. If a regular shield or no shield at all is equipped the cockatrice will shoot out beams from its eyes and quickly reduce a player's stats to dangerously low levels and rapidly hit 9's. They have few hitpoints and do not hit particularly hard unless the player forgets the mirror shield. The attack style crush seems to be accurate.

Drops
100% Drop: Bones

Weapons/Armour:
 * Iron sword (common)
 * Steel dagger
 * Steel platelegs
 * Steel longsword
 * Rune spear
 * Dragon Spear (very rare)
 * Iron javelin(5)
 * 5 Rune Javelins (rare)
 * Iron boots
 * Mystic boots (rare)

Runes:
 * 2 Water runes
 * 7 Fire runes
 * 2, 4, or 6 Nature runes (common)
 * 2-3 Law runes

Summoning Charms:
 * Gold charm
 * Green charm (common)
 * Crimson charm
 * Blue charm

Herbs:
 * Guam
 * Marrentill
 * Harralander
 * Tarromin
 * Irit
 * Avantoe
 * Kwuarm
 * Dwarf Weed
 * Ranarr
 * Lantadyme
 * Cadantine

Seeds:
 * Potato
 * Onion
 * Cabbage
 * Strawberry

Other drops:
 * Level 2 Clue Scroll (fairly common)
 * Limpwurt root (very common)
 * Cockatrice egg (common)
 * Cockatrice head (very rare)
 * Mithril ore
 * Gems
 * Half of a key
 * Chaos talisman
 * Coins: 1, 5, 15, 28, or 62 (very common)