These aren't real words, it's mimicking young toddlers who can't pronounce the real words. Notice the grammar and syntax is also that of a young child just learning to speak.
pittie = pitty, from pitty-patty (onomatopoeia for the slapping sound bare feet make), also used in children's games where parents/children count toes
two footen = either an archaic way of saying 'two footed', or he's using just using poetic license and making up a word (this one isn't baby talk)
Gamma = Gramma/Grandma
Dood = good
knicklebockies= knickerbockers (old-fashioned stye of pants primarily for young boys whichhad short legs tucked into socks just below the knee.)
Student or Learner