Not including Magikarp, are there any Water-type Pokemon that cannot learn the move Ice Beam?
Almost all Water types can use Ice Beam -Bulbapedia
Keldeo and Rotom-W, and the Water-Toad family (Tympole, Palpitoad, and Seismitoad) can't learn Ice Beam.
Other than that, I believe all other water types can learn Ice Beam.