I'm not sure who is stabbed and who is snarling here.
" Ralf launched himself like a cat; stabbed, snarling, with the spear, and the savage doubled up."
Thanks in advance
This is a quote from Chapter 12 of the novel "Lord of the Flies" by William Golding.
Here's some context from about 3 paragraphs before your quote:
Ralph fastened his hands round the chewed spear and his hair fell. Someone was muttering, only a few yards away toward the Castle Rock. He heard a savage say "No!" in a shocked voice; and then there was suppressed laughter. He squatted back on his heels and showed his teeth at the wall of branches. He raise [sic] his spear, snarled a little, and waited.
Ralph attacks again at the time of your quote, about 3 paragraphs after this:
A smallish savage was standing between him and the rest of the forest, a savage striped red and white, and carrying a spear. He was coughing and smearing the paint about his eyes with the back of his hand as he tried to see through the increasing smoke. Ralph launched himself like a cat; stabbed, snarling, with the spear, and the savage doubled up.
We can parse the word snarling in the last sentence (which is also your quote) as a parenthetical, so that it's Ralph doing the stabbing with the spear, snarling as he does so.