Akaname means Filth Licker so...
Appearance of Akaname on Yokai.com:
Akaname is a small, goblin-like yokai which inhabits only the dirtiest homes and public baths. It is about the size of a child or a small adult, though it generally appears much smaller due to its hunching posture. It has a mop of greasy, slimy hair on top of its head. Its body is naked, its skin greasy like its hair. Akaname come in many colors and varieties, ranging from a dark mottled green reminiscent of mold, to the ruddy pink color of bedsores. They come in both one-eyed and two-eyed varieties, and can have anywhere from one to five fingers and toes. All akaname have an extremely long, sticky tongue with which they lap up the slime, grease, hair, and other filth found in bath houses and behind toilets.
BEHAVIOR of Akaname on Yokai.com:
Like cockroaches, rats, lice, and other pests, akaname detest clean, well-kept homes, and only appear where the owners show a complete lack of sanitary discipline. They are shy and stay clear of humans, scattering in the light like cockroaches. They can spread disease, however, so it is a good idea to keep bathrooms and houses clean enough that akaname do not wish to settle down.
Akaname on Wikipedia:
The akaname is the "personification of the fear of using a dark bathroom late at night". It is said to come out at night to lick up the grime and dirt that accumulates in unclean bathrooms.
Lickyyung on Pokedexes:
Blue: Its tongue can be extended like a chameleon's. It leaves a tingling sensation when it licks enemies.
Yellow: Its tongue spans almost 7 feet and moves more freely than its forelegs. Its licks can cause paralysis.
Silver: Its long tongue, slathered with a gooey saliva, sticks to anything, so it is very useful.
Alpha Sapphire: Whenever Lickitung comes across something new, it will unfailingly give it a lick. It does so because it memorizes things by texture and by taste. It is somewhat put off by sour things.
I made all the similarities Bold and major differences Italic.
Basically... they don't seem to have enough similarities for Lickitung to be based on it. For one thing, it comes out in the night however, you can find Lickitung in any time of the day in the games. Another thing, they act like cockroaches and flee once startled and should be skinny enough to flee quickly, and it is. Lickytung on the other hand seems a bit chubby don't you think? Another difference is the fact that Lickitung has a TAIL. Finally this Yokai hangs out in the bathroom. Does that even exist in the Pokemon World? Unless of course you were playing Pokemon Go and needed a Bathroom break and a Lickitung appeared on the screen.