A man stabbed a 70-year-old in a random attack "just for the sake of killing somebody" as they crossed paths at a remote beauty spot, a jury has heard.
Moses Christensen walked about 20 miles (32km) to Brown Clee Hill, Shropshire, where he attacked Richard Hall near the summit.
The 22-year-old himself described the attack as "savage" and "animalistic", Stafford Crown Court heard.
Mr Hall, of Perton, Staffordshire, was found dead on 14 August.
Opening the case against Mr Christensen, who denies murder, prosecutor Adrian Keeling QC told jurors the defendant had armed himself with two combat knives and was being sought by police after telling a relative he wanted to kill three of his past teachers and "eat the flesh of one of them".
"The defendant had no reason at all to bear Mr Hall any ill will, let alone to kill him," Mr Keeling said.
"But the defendant, by his own admission, wanted to kill someone and Mr Hall, walking on his own, was chosen by the defendant as an easy target."
Mr Hall told his wife he was going for a walk and would be back in time for something to eat, the court heard.
Mr Christensen, of Corser Street, Oldswinford, Stourbridge, told police after he was arrested how he had seen Mr Hall emerge "out of the fog" on the hill.
The pair had greeted each other, before Mr Christensen jumped on his victim, stabbing him multiple times.
Describing the defendant's "chilling" account of what happened, Mr Keeling told jurors: "In interview he said this: 'I would like to point out that this wasn't just an outburst of emotion or something'."
'Lifelong desire to kill'
Alleging the defendant was intent on murder, Mr Keeling said he wanted to kill someone, "just for the sake of killing somebody" - as a "sort of lifelong desire and ambition".
The court heard he said he felt "minimal" remorse when asked by police.
The jury was told they would be required to decide whether the defendant, who was said to have autism spectrum disorder, was guilty of murder or manslaughter on the grounds of diminished responsibility.
"The simple reality is that he killed because that is exactly what he wanted to do," Mr Keeling concluded.
The trial continues.