I've seen a few online stores that specialize in anime merchandise carry L Lawliet body pillows, but availability can be pretty hit or miss. Sites like Redbubble or Etsy sometimes have fan-made designs, though the quality varies. Official merch is harder to come by since 'Death Note' isn't as actively promoted as newer series, but checking Japanese import sites like AmiAmi or Mandarake might yield results.
If you're okay with unofficial prints, AliExpress and eBay often have listings, but be cautious about seller ratings. I snagged one last year from a small artist on Twitter who did limited runs—those tend to feel more unique than mass-produced ones. Just remember to double-check dimensions if you’re picky about pillow size!