Loki

"You must be very proud of your son," said a kindly woman to Frigg. Frigg did not recognise the woman, but the woman beamed when she looked at Balder, and Frigg was indeed proud of her son. Everybody loved him, after all. "But won't they hurt him, the poor darling? Throwing things at him like that? If I were his mother, I would be afraid for my son."
"They will not hurt him," said Frigg. "No weapon can hurt Balder. No disease. No rock. No tree. I have taken an oath from all the things there are that can harm."
"That's good," said the kindly woman. "I'm pleased. But are you sure you didn't miss any of them?"
"Not a one," said Frigg. "All the trees. The only one I did not bother with was misteltoe—it's a creeper that grows on the oak trees west of Valhalla. But it's too young and too small ever to do any harm. You could not make a club from misteltoe."
"My, my," said the kindly woman. "Mistletoe, eh? Well, truth to tell, I wouldn't have bothered with that either. Much to weedy."
The kindly woman had begun to remind Frigg of someone, but before the goddess could think who it was, Tyr held up an enormous rock with his good left hand, held it high above his head, and crashed it down on Balder's chest. It disintegrated into dust before ever it touched the shining god.
When Frigg turned back to talk to the kindly woman, she was already gone, and Frigg thought no more about it. Not then.
Loki in his own form, travelled to the west of Valhalla.