"hockey disk," 1891, possibly from puck (v.) "to hit, strike" (1861), which perhaps is related to poke via notion of "push." Another suggestion traces the noun to Ir. poc "bag." Puckster headlinese for "ice hockey player" is attested from 1939.
"mischievous fairy" (in "A Midsummer Night's Dream"), probably from pouke "devil, evil spirit" (c.1300), from O.E. puca, cognate with O.N. puki "devil," of unknown origin (cf. pug). Capitalized since 16c. His disguised name was Robin Goodfellow.
1530, from hob "elf," from Hobbe, a variant of Rob (cf. Hick for Richard, Hodge for Rodger, etc.), short for Robin Goodfellow, elf character in Ger. folklore, + goblin.