Catablepon

Catablepon are monsters that look like green bulls and are found on the third level of the Stronghold of Security. They are aggressive to all players, regardless of combat level. They use the magic spell, Weaken (which looks like a spraying white sparkle), to drain strength by up to 15% of their opponent's maximum level, so it would be advisable to bring a Dragon battleaxe to boost up your strength whenever the Catablepon uses this spell on you; training on these is not advised, as Weaken can be quite significant, unless you have a strength potion or a Dragon battleaxe. It should be noted that they can melee-attack and cast Weaken at the same time and that they can only cast it when next to you. It is also possible that they can damage and miss with Weaken, or miss while the spell works.

They also seem to have an unusually high drop rate for clue scrolls. In the north-western most room of the third level of the Stronghold of Security, there is an excellent safe spot for using Magic, Ranged, or using a halberd on catablepon, to the immediate west of the square patch of tendrils by the skeletons, in the centre east room there is also a safe spot. Catablepons are unique among F2P monsters in that it has a two-space melee attack, but only hits diagonally.

Catablepon cease aggressiveness after a while. They will become aggressive again however, if you walk a little ways away and come back.

Drops
100% drop: Bones

Runes

 * Fire rune (15) (very common)
 * Water rune (7)
 * Chaos rune (7)
 * Law rune (2)
 * Cosmic rune (2-4)
 * Body rune (7)

Gems

 * Uncut sapphire
 * Uncut emerald
 * Uncut ruby
 * Uncut diamond

Seeds (members only)

 * 1 Tomato seed
 * 1 Onion seed
 * 1 Sweetcorn seed
 * 1 or 4 Potato seeds
 * 3 Cabbage seeds
 * 4 Evil turnip seeds

Herbs (members only)

 * Grimy guam
 * Grimy marrentill
 * Grimy avantoe
 * Grimy kwuarm
 * Grimy irit
 * Grimy cadantine
 * Grimy ranarr
 * Grimy lantadyme
 * Grimy dwarf weed
 * Grimy tarromin

Other drops

 * Pure essence (15 or 30) (Noted) (15 Common, 30 rare)
 * Rune Javelin (m) (5) (extremely rare)
 * Clue scroll (m) (level 2) (uncommon)
 * Unlit torch (m) (very common)
 * Nature Talisman (m) (rare)
 * Half of a key (m)
 * Coins (15-100) (common)
 * Adamant med helm
 * Rune essence (15) (Noted)
 * Adamant arrows (5-14)
 * Mithril arrows (5-17)
 * Coal (3-7) (Noted)
 * Trout
 * Salmon
 * Eye of Newt (very common)
 * Top of sceptre (very rare)
 * Mithril bolts(m) (5-15) (very rare)
 * Black Full Helm (very Rare)

Trivia

 * Players who tried to say "catablepon" in-game once found that the last three letters were blocked by the chat filter; this was later fixed.
 * This monster was one of several to be created in-game after having been suggested by a player in the Suggest-A-Monster sticky in the Suggestions section of the RuneScape Forums.
 * Catablepons are based on a mythical Ethiopian creature called a Catoblepas.
 * At one point, the weaken spell that they cast seemed to only reduce a maximum of 9 in the strength stat. Tests have shown that it does in fact decrease the stat by 10.
 * If you get Catablepons as your slayer task from Mazchna the slayer master in Canifis and you ask for a tip you will be told that "Catablepon are cow-like, magical creatures that mainly live in the Stronghold of Security. Beware their weakening glare; cutting off their head should help". When Mazchna says this it is a reference to Ethiopian mythology. In Ethiopian myththology, the monster Catoblepas was slain and its head chopped off as a trophy - there is no way to do this in-game.
 * After a Catablepon takes a hit it will shake his head like it actually felt pain
 * The level 68 catablepons seem to run away if its health is low and you eat food. but this is rare