Ikrima, the militant targeted by US special forces in a failed weekend raid, is a Somali-based thinker, planner and operator who has relentlessly plotted attacks on neighbouring Kenya, intelligence services and analysts believe.
Kenyan and Western security agencies have identified Ikrima - the nom de guerre of Abdikadar Mohamed Abdikadar - as the link man for commanders of the al- Shabab Islamist group in Somalia with al-Qaeda and Kenya's home-bred militants.
They have not established that Ikrima, a Kenyan of Somali origin who spent several years in Norway, was involved in last month's attack on a Nairobi shopping mall that killed 67 people, for which al-Shabab has claimed responsibility.
But he plotted to attack Kenya's parliament, assassinate Kenyan politicians and hit UN offices in Nairobi, according to a leaked Kenyan intelligence report.
These plans failed, but so too did the US Navy SEALS mission into Barawe, a militant stronghold on Somalia's southern coast. The special forces team pulled out after a gun battle without capturing Ikrima, named after a figure in Islamic history who first fought against Prophet Mohammed but then converted to become one of his most valiant commanders.
"He is a planner who is relentless in coming up with operations in Kenya," said Matt Bryden, a former co-ordinator of the United Nations Somalia and Eritrea Monitoring Group. "He is one of the thinkers, planners, operational practitioners."
One defector from al-Shabab, who now works with Somali intelligence, described Ikrima as a well-connected man in his 30s able to mastermind operations across the border into Kenya.
In a security document leaked a week after the Westgate raid, Kenya's national intelligence service detailed plots masterminded by Ikrima to attack parliament, a restaurant popular with Somali officials, the UN headquarters in Nairobi and Kenyan politicians.
The plans had been sanctioned by al-Qaeda in Pakistan.