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.

They also seem to have an unusually high drop rate for clue scrolls. In the northwestern most room of the third level, 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 2-space melee attack, but only hits diagonally.

Drops
100% drop: Bones

Runes

 * 15 Fire runes
 * 7 Water runes
 * 7 Chaos runes
 * 2 Law Runes
 * 4 Cosmic runes

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

Charms(Members only)

 * Gold charm (common)
 * Blue charm
 * Crimson charm
 * Green charm

Other drops

 * 15 Pure essence (noted) (Common)
 * 30 pure essence (noted) (rare)
 * 5 Rune Javelin (m) (extremely rare)
 * Level 2 Clue scroll (m)
 * Unlit torch (m) (very common)
 * Nature Talisman (m) (rare)
 * Half of a key (m)
 * 15-100 Coins
 * 15 Rune essence (Noted)
 * 5-14 adamant arrows
 * 5-14 mithril arrows
 * 3-7 noted Coal
 * Trout
 * Salmon
 * Eye of Newt
 * Adamant medium helmet
 * Top of sceptre - part of the Skull sceptre (slightly rare)
 * Nothing

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.
 * Catablepon are based on a mythical Ethiopian creature called a Catoblepas.
 * When asking a Slayer Master for a tip about this creature, you can get the reply: "Catablepon are cow-like, magical creatures that mainly live in the Stronghold of Security. Beware their weakening glare; cutting off their head could help." This may hint that Catablepon may someday appear in some other location. It also indicates that 'Catablepon' is both the singular and plural form of the word. This also may be a reference to the Medusa, a creature from Greek mythology.