The Strongest monster in RuneScape (based on combat level) is currently the Kalphite King, having a combat level of 230. Although the Ferret of Doom and its friends are portrayed as having a combat level of 9001, they are not included as they are not actually monsters and likely only appear to have those levels due to Thok's phobia of ferrets.

Past record holders

Overall strongest monster past record holders

Monster	Level	Timeframe	Duration
Kalphite King	230	14 January 2013 - present	115 days to date
Queen Black Dragon / Nex	220	20 November 2012 - 14 January 2013	55 days
Queen Black Dragon	2100 (pre-EoC RS2)	29 May 2012 - 20 November 2012	176 days
Nex	1001 (pre-EoC RS2)	10 January 2011 - 29 May 2012	505 days
Corporeal Beast	785 (pre-EoC RS2)	15 September 2008 - 10 January 2011	847 days
TzTok-Jad	702 (pre-EoC RS2)	4 October 2005 - 15 September 2008	1077 days
Kalphite Queen	333 (pre-EoC RS2)	7 September 2004 - 4 October 2005	392 days
King Black Dragon	245 (RSC) / 276 (pre-EoC RS2)	24 September 2002 - 7 September 2004	714 days
Black dragon	200 (RSC)	27 February 2002 - 24 September 2002	209 days
Elvarg	110 (RSC)	23 September 2001 - 27 February 2002	157 days
Greater demon	87 (RSC)	13 August 2001 - 23 September 2001	41 days
Lesser demon	79 (RSC)	11 June 2001 - 13 August 2001	63 days
Ice giant	68 (RSC)	6 April 2001 - 11 June 2001	66 days
Moss giant	62 (RSC)	5 February 2001 - 6 April 2001	60 days
Black Knight	46 (RSC)	4 January 2001 - 5 February 2001	32 days

For more information on the monsters, please see their individual pages listed above by clicking on the links.

Free-to-play strongest monster past record holders

Monster	Level	Timeframe	Duration
Revenant knight	140 (was 126 in pre-EoC RS2)	25 February 2009 - Present	1535 days to date
Hellhound (strongest non-revenant)	132 (was 127 in pre-EoC RS2)	16 June 2009 - Present	1423 days to date
Greater demon	92 (pre-EoC RS2)	24 March 2004 - 15 June 2008	1545 days
Elvarg	110 (RSC) (83 in pre-EoC RS2)	23 September 2001 - 24 March 2004	913 days
Greater demon	87 (RSC)	13 August 2001 - 23 September 2001	41 days
Lesser demon	79 (RSC)	11 June 2001 - 13 August 2001	63 days
Ice giant	68 (RSC)	6 April 2001 - 11 June 2001	66 days
Moss giant	62 (RSC)	5 February 2001 - 6 April 2001	60 days
Black Knight	46 (RSC)	4 January 2001 - 5 February 2001	32 days

Quest monster past record holders

Monster	Level	Timeframe	Duration
Nomad	699 (pre-EoC RS2) (currently 200)	11 January 2010 - Present	1213 days to date
Balance Elemental	454 (pre-EoC RS2)	26 November 2008 - 11 January 2010	391 days
The Inadequacy	343 (pre-EoC RS2)	15 May 2007 - 26 November 2008	561 days
Black Dragon (Freeing Sir Amik Varze)	227 (pre-EoC RS2)	15 March 2006 - 15 May 2007	426 days
Jungle demon	195 (pre-EoC RS2)	6 December 2004 - 15 March 2006	464 days
Nezikchened	187 (RSC)	20 August 2003 - 6 December 2004	473 days
Black Demon (The Grand Tree)	175 (RSC)	12 September 2002 - 20 August 2003	342 days
Chronozon	121 (RSC)	9 April 2002 - 12 September 2002	156 days
Elvarg	110 (RSC)	23 September 2001 - 9 April 2002	198 days
Count Draynor	43 (RSC)	28 January 2001 - 23 September 2001	238 days
Delrith	30 (RSC)	4 January 2001 - 28 January 2001	24 days

Top 10 strongest monsters

Position	Monster	Level
1	Kalphite King	230
2	Queen Black Dragon	220
3	Nex	220
4	Corporeal Beast	210
5	K'ril Tsutsaroth	210
6	Commander Zilyana	210
7	Kree'arra	210
8	General Graardor	210
9	Nomad	200
10	Kalphite Queen	200

Notes

• The list does not include Dungeoneering bosses.
• A comprehensive all inclusive list of fightable bosses (includes Dungeoneering bosses) would be levels : 264, 258, 252, 230, 220, 220, 210, 210, 210, 210, 210. The first 3 are the 3 highest level versions of World-Gorger Shukarhazh.