First off,i'll talk about some block entities,updates for existing mobs,and new mob mechanics:
and all fish,bird,mammal,and reptile mobs drop bone shards occasionally on death...

Block entities:
1.falling sand/red sand/gravel/mud/pebble block:
when a solid block under any of the 5 blocks above,it will become an entity,falls,and if it lands,it will turn back to a block,but if it lands on a mob or player,the block could suffocate them,and they could die if not escaped in time.

2.shooting/flying/falling arrow:
when an arrow,it will be turned into an entity,until it hits a mob,harms the mob(not players,it sticks on them for 1 minute and 30 seconds,when it despawns),and it instantly despawns,but other wise,it will take 1.5 till it despawns on it's own.when skeletons shoot arrows at you,spawn arrow entities.

3.fireball:
spawned by ghast,and possessed humans(looks similar to the Herobrine skin in Minecraft,and only spawn in void diemesion)as a/form of attack,and if fire charges are despinced by a despincer.and fire balls explode on contact.

4.snowballs:
mine snow sheets(spawned on surfaces of blocks when it snows),or snow blocks with a shovel,or kill a snow golem to get snowballs,and you can though snowballs like you can with eggs,and despawn on contact with anything but,air,water,oil,lava source blocks,or other snowballs,and when they come in contact with entities,or blocks,will make particles based off the texture of the snowball item.

5.ignited TNT:
when in contact with fire,lava,fire changes,explosions,and flint&steel,TNT will repeatedly flash white,make a hissing sound,falls(if no block was exactly under it),and it will explode in 10 seconds.

6.thrown bomb:
bombs are crafted by 1 gunpowder,1 silk,and 3 iron ingots,or dropped occasially by living bombs.and if thrown, explode in 6 seconds.but can be tapped on to become an item in the inventory,and will disable the explosion count down.

New mob mechanics:

Animal hunger:it will take a total of 14 game days. And there can be an option name "more hungry animals"(is activated by default)and if disabled,animals won't die of hunger,but wolves,bears,and any other animals that attack other animals will still kill certain mobs,but don't destroy terrain(plants) and you will have a slightly easier time on the game,.but to have a more challenging,realistic experience,keep it enabled.

Updates(improvements) to existing mobs:

1.turkeys:
add an actual baby turkey model to the game,Add turkey eggs,make them drop feathers.

2.wolves,dog,and cats:
Dogs and cats will no longer naturally spawn anymore,but will appear when you tame wolves and ocelots.wolves can be breed by animal meat,drop fur,and bone shards. And right now,wolves make a hostile sound while not hostile,so can you change the hostile sounding Idle sound,to be a sound when Their hostile,make the howling sound only when it's night time,on the full moon phase,and add a new non hostile sounding wolf sound for when Their passive.and they will also attack sheep,cows,pigs,chickens,turkeys,and horses.

3.cows,horses,and sheep:
sheep can be dyed,some naturally spawn with certain wool colors,also can drop raw mutton(cooked if death by fire),sheep and cows and horses destroy grass,wild wheat,and flowers. Horses would be ridden with saddles,have multiple skins,and 4 other forms(donkeys,mules,zombie horses,and skeleton horses).

4.zombies:
Blue and Green zombies will have an equal chance to spawn as female ones,and if a male and female zombie are 20 blocks away from the player for 8 seconds,will walk side to side together,then 8 more seconds later, they will start to go in lovemode,and spawn a baby zombie(50%chance male,50% chance female),but zombies will sometimes spawn as babies(which are faster than adults,like on Minecraft,but will burn in daylight,unlike in Minecraft.),zombies,pumpkin heads,and skeletons will sometimes spawn wearing armor,and around Halloween in real time,will sometimes spawn wearing carved pumpkins on their heads,and sometimes spawn holding items,and weapons,and will attack NPC villagers,and animals,and zombies can sometimes spawn as zombie villagers that can be cured,just like pumpkin heads and zombies now, by a golden apple and throw a splash potion of weakness at them and wait for 8 minutes and you will get a normal villager,zombie villagers look exactly like the zombie skin(default player skin one not mob one)but with it's arms stick out,and their's not a gender separate skin,unlike normal villagers which look like the some of the normal default player Skins,but you can trade with them,villagers can breed,become zombies if killed by zombies,become pumpkin heads if killed by pumpkin heads,and don't have name tags,and make humming sounds(guys humming for males with higher pitch voice for baby male villagers,and woman humming for females with higher pitch voice for baby female villagers).

5.Pumpkin heads:
when shears are used on a pumpkin head to remove the pumpkin one their head,and they actually have a normal blue zombie head and then can't throw pumpkins at you anymore.And there are female,baby male,and baby female pumpkin heads. Female pumpkin heads eyes and mouth is blue instead of Orange(the eye and mouth color of the original/male pumpkin heads)and the female pumpkin heads have hair going through the pumpkin their wearing,(similar hair style as the female zombies,female villagers,and the Alex skin in Minecraft.)and some pumpkin heads will spawn with no pumpkin,and their head is that of the male/female(depends on gender of the pumpkin head)blue zombies,and then can sometimes spawn holding tools,and items.and when the pumpkin they throw hits something,make it make pumpkin particles and not potato particles. On the next one,I'll talk about the new mobs to add to the game.