I was making my own Pokemon texture pack and this has really given me some inspiration. Don't worry, I won't directly copy anything.

Super gemacht

can creepers = voltorb, skeletons = marowak, iron golem = registeel, zombie = canidos, turtles = tirtouga, husk = cancea, drowned = empoleon, bats = crobat, phantoms = gliscor, sorry if i seem rude and too suggestive. i just think this is a neat idea.

I see someone said the Ender dragon should be Charizard but maybe it could be Latios, Latias, Lugia, or even flygon because alot of people doing pokemon packs make Charizard the EnderDragon. But make the Wither Hydreigon because it has three heads. Nice work so far so I gave you a diamond you have alot of potential and I hope you do more packs after this one.

Here's a few suggestions although i'm not sure if they were suggested or not and some may be obvious too, anywyas I hope these help ^^

Bat = Zubat
Fox = Vulpix
Snow Varient Fox = Alolan Vulpix
Polar Bear = Beartic
Panda Bear = Pangoro(if only could give the babies a separate texture then they could be pancham)
Phantom = Masquerain(might work since the phantom has a tail bit but could be better options like gligar)
Shulker = Make it a pokeball or something like it with a rare pokemon sticking it's head out(like ditto or mew)
Cave Spider = Spinarak(joltik works too but Poison is more fitting with Spinarak)
Spider = Ariados(same thing with galvantula)
Skeleton = Maybe Marowak

Suggestion: Cod or Salmons or both could be Magikarps (not sure if they are or not, gonna download the texture pack.) would be very epic