So I was thinking how sad it is that Croc never gets tickled by the grappling beam because that's what he is guarding. Then it hit me, you can get grapple through GT code. So the idea is get GT code and tickle croc till Samus is dead (grappling Crocomire deals damage). I have a run I could upload if anyone is interested.

its not grappling croc that deal DMG but its the fact you are close to croc that deal DMG, basically his claw

It's also possible to get Grapple without killing Croc by X-ray Climbing past Croc's room. This can be used in beginner-friendly routes of RAMBO: