Question: Who created Humphrey the Bear and Pluto the Pup?

Context paragraphs:
Rugged Bear: Rugged Bear is a 1953 American animated short film produced by Walt Disney Productions and released by RKO Radio Pictures.  The cartoon follows Humphrey the Bear (in his 2nd appearance) as he takes refuge in Donald Duck's cabin during hunting season by disguising himself as a bearskin rug.  The film was directed by Jack Hannah and features the voices of Clarence Nash as Donald, Jimmy MacDonald as Humphrey, and an uncredited narrator.

Humphrey the Bear: Humphrey the Bear is a cartoon character created by the Walt Disney studio in 1950.  He first appeared in the Goofy cartoon "Hold That Pose", in which Goofy tried to take his picture.  After that he appeared in four classic Donald Duck cartoons: "Rugged Bear", "Grin and Bear It", "Bearly Asleep", and "Beezy Bear".  Disney gave him his own series in 1955, but only two films resulted ("Hooked Bear" and "In the Bag") before Disney discontinued making theatrical short subjects.  When the shorts division closed, Humphrey was the last of only seven Disney characters who had been given a series of their own, starring in cartoons who opened with their own logo (the six others were Mickey Mouse, Donald Duck, Goofy, Pluto, Chip 'n' Dale (counting as one), and Figaro).

Fatso the Bear: Fatso The Bear is a Walter Lantz character, who made his first appearance in the cartoon "Hunger Strife", in 1960.  His final appearance was in 1961, in "The Bear and the Bees".  The bear is essentially a "clone" of Disney's Humphrey the Bear, in terms of physical appearance, gruff voice, and personality.  This makes sense, as the character was created by Jack Hannah, who had directed some Donald Duck cartoons at Disney back in the mid-1940s into the 1950s.

Chucklewood Critters: Chucklewood Critters is an American line of television specials and an animated television series created by former Hanna-Barbera animators, Bill Hutten and Tony Love, which centered on two North American woodland animals: Buttons, a young bear cub, and Rusty, a young fox pup.  It started as a Christmas special in 1983 called " The Christmas Tree Train", followed by eight more holiday/seasonal specials.  In 1997 it was developed into a series entitled "The New Chucklewood Critters", which ran for two seasons.

PARC Universal Packet: The PARC Universal Packet (commonly abbreviated to PUP or PuP, although the original documents usually use Pup) was one of the two earliest internetwork protocol suites; it was created by researchers at Xerox PARC in the mid-1970s.  (Technically, the name "PUP" only refers to the internetwork-level protocol, but it is also applied to the whole protocol suite).  The entire suite provided routing and packet delivery, as well as higher level functions such as a reliable byte stream, along with numerous applications.

Pluto (Disney): Pluto, also called Pluto the Pup, is a cartoon character created in 1930 at Walt Disney Productions.  He is a yellow-orange color, medium-sized, short-haired dog with black ears.  Unlike most Disney characters, Pluto is not anthropomorphic beyond some characteristics such as facial expression, though he did speak for a short portion of his history.  He is Mickey Mouse's pet.  Officially a mixed-breed dog, he made his debut as a bloodhound in the Mickey Mouse cartoon "The Chain Gang".  Together with Mickey Mouse, Minnie Mouse, Donald Duck, Daisy Duck, and Goofy, Pluto is one of the "Sensational Six"—the biggest stars in the Disney universe.  Though all six are non-human animals, Pluto alone is not dressed as a human.

Mother Pluto: Mother Pluto is a Silly Symphonies cartoon released on November 14, 1936, directed by David Hand.  The cartoon features the adorable pup, Pluto.

Here's Humphrey: Here's Humphrey was an Australian children's television series first aired on Monday 24 May 1965 on the Nine Network.  It featured a character known as Humphrey B. Bear.  In the early days Humphrey was known as "Bear Bear" and was named "Humphrey B. Bear" as the result of an on-air competition.  "Here's Humphrey" has become one of the most successful programs for pre-schoolers in Australia and is one of the longest running children’s television programs in the world.

Beezy Bear: Beezy Bear is a Disney animated short featuring Donald Duck, who appears as a beekeeper.  This is Humphrey the Bear's fifth appearance.  The cartoon portrays Humphrey as a honey-stealing bear.

Humphrey B. Bear: Humphrey B. Bear is an Australian children's television series and its fictional character namesake is an icon of Australian children's television.  "Humphrey B. Bear" was first broadcast on Adelaide's NWS-9 on Monday, 24 May 1965.  The show became one of the most successful programs for pre-schoolers in Australia.  The part of Humphrey was originally played by Edwin "Ted" Duryea, (c.1930-2009) an actor, singer and dancer whose human identity was never revealed.

Supporting paragraphs: Humphrey the Bear Pluto (Disney)
Answer: Walt Disney Productions