This .mcaddon fixes over 30 vanilla bugs, including entity behaviors, spawning/despawning, sound properties, and rendering offsets. It does not replace any actual textures or sounds so it should be compatible with most texture packs. All of the fixes are listed below with Mojang bug tracker references. Note that since the pack includes behavior fixes it is not compatible with earning achievements.
Vanilla bugs fixed by this add-on
“MCPE-XXXXXX” below are keys to bug reports on Mojang’s public bug tracker. You can read more about each bug on the associated report.
MCPE-34746 Evokers summon vexes more quickly (matches Java)
MCPE-42373 Vindicators and Evokers no longer retaliate when shot by Pillagers
MCPE-44606 Ravager now hostile toward wandering traders
MCPE-45531 Ravager collision box increased (matches Java)
MCPE-48145 Ravager movement speed increased (matches Java)
MCPE-45820 Vindicator and pillager wandering speed decreased
MCPE-50207 Ravager targeting range increased (matches Java)
MCPE-51329 Ravager now breaks wither roses
MCPE-60680 Ravager attack reach increased (fixed by collision fix above)
MCPE-84371 Pillagers and Ravagers now hostile toward snow golems
MCPE-91598 Patrols now swarm/attack as a group (this existed in 1.14 but was removed in 1.16)
MCPE-115094 Vexes no longer retaliate against evokers
MCPE-35202 Ghast fireball now comes from its mouth instead of the top of its head
MCPE-45311 Ghast no longer holds charge when player leaves its targeting range
MCPE-50207 Ghast targeting range increased horizontally and decreased vertically (matches Java)
MCPE-44312 / MCPE-102302 Trader llamas can now despawn if unleashed
MCPE-70664 Hatched turtles no longer despawn
MCPE-75470 Patrol vindicators can now despawn
MCPE-106557 Phantoms no longer overspawn on Sim6+
MCPE-48233 Fox health decreased (matches Java)
MCPE-60895 Removed mob collision for lodged tridents (note: does not affect hitbox or functionality of trident killers)
MCPE-87711 Removed mob collision for XP orbs
MCPE-105369 Husk height decreased (matches zombies and other humanoids)
MCPE-106439 XP now rises as fast as items and mobs in soul sand bubble columns
MCPE-109330 XP now sinks as fast as items and mobs in falling water
MCPE-14420 / MCPE-48919 Click sound volume now lowers with distance
MCPE-35222 Ghast sound volume lowers more noticeably with distance (now starts to attenuate at 24 blocks, used to be 100)
MCPE-90160 Minecart sounds now stop at 16 blocks
MCPE-117964 Eggs now make a breaking sound when destroyed by a ravager
MCPE-45311 Ghast returns its face to normal when it does not have a target
MCPE-114253 Squid/glow squid texture now aligned with its collision box
MCPE-110282 XP orb texture now aligned with its collision box (note: this does not fix desyncing)
Updated featured image to represent some of the fixes in the pack: husks can fit in 2-high spaces, patrols attack as a group, ghasts shoot fireballs from their mouths, and glow squids body is rendered centered on its position.
Import the .mcaddon file, then enable the behavior pack on your world. It should add the resource pack automatically.
It is possible to use just the resource pack, but doing so will allow ghasts to hold their charges when out of shooting range without appearing to be charged and without making a warning sound when they re-target you.