The Crawlers have the appearance and abilities of Nightcrawler, indicating that this is probably the source of the majority of their genetic material. Sublime can clone large numbers of Crawlers at a time in his factory, and they remain obedient to his will. Using samples of DNA from other mutants, Sublime was able to give his Crawlers the abilities of other mutants that he had encountered over the years.
Teleportation - Taken from Nightcrawler
Optic Blasts - Because Beast's proximity with Cyclops it is presumably that he is the source of their optic blasts. Unlike Cyclops, the Crawlers are able to control their blasts by turning them off.
Mind Consumption - Beast had discovered a Mind Parasite in one of the mutants he had captured, and gave this ability to one of his Crawlers. It allowed him to consume the minds of those around him, taking them under his control.
Replication - The Crawlers have the ability to generate exact copies of themselves with the same powers. This power was adapted fromMadrox (Multiple Man).
Wings - Some of the Crawlers have wings, giving them the ability to fly. This ability comes from an unknown source. They are most likely not from Angel despite Beast's proximity to him because they resemble bat wings and lack feathers.