Pehkui — Minecraft Mod

Pehkui — Minecraft mod 

Pehkui is a library mod for Minecraft Java Edition that allows you to change the size of almost any entity in the game: making a player or mob smaller or larger than the default. Along with visually scaling the entity, it proportionally adjusts related attributes — movement speed, interaction reach, fall damage, explosion radius, health, and attack damage.

The tool itself does not add items, blocks, or new mobs. It provides a scaling mechanic that can be controlled via a dedicated command or through other mods that use it as a foundation.

What exactly changes

The core principle: a set of separate multipliers is stored for each entity — individually for height, width, damage, interaction reach, health, speed, and other parameters. It's not a single global number, but multiple parallel values, some of which are tied to each other. For example, the pehkui:height type simultaneously affects hitbox height, eye level, and third-person camera distance — if you change just the height, the related parameters adjust automatically.

An enlarged CREEPER compared to a normal one.

This system allows you to control behavior precisely: you can increase only the damage without changing the size, only the speed without affecting health, or just the interaction reach without impacting the hitbox.

Shrinking the player and comparing them to a standard door.

The /scale command

If there are no other mods in the modpack that add a scaling interface, you can manage sizes directly via a console command. It only works for a player with operator privileges.

The basic syntax sets or modifies the value for a specific scale type and a specific entity:

/scale set <value> [<entity>]

/scale set <scale_type> <value> [<entity>]

/scale (add|subtract|multiply|divide) <value> [<entity>]

/scale (add|subtract|multiply|divide) <scale_type> <value> [<entity>]

/scale get [<entity>]

/scale reset [<entity>]

The <value> is a multiplier. 1.0 is the standard size, 0.5 is half the size, and 2.0 is twice the size. If the scale type is not specified, the operation applies to pehkui:base — the base scale, which simultaneously affects width, height, movement, drops, projectiles, explosions, and visibility.

There is a separate subcommand to delay the transition between values. Without it, the scale changes instantly — in one tick. With it, the transition is stretched over the specified number of ticks and looks smooth:

/scale delay set <ticks> [<entity>]

/scale delay set <scale_type> <ticks> [<entity>]

For example, 60 ticks is three seconds of smooth growing or shrinking.

A shrunken player next to a standard CREEPER. 

Scale types

In total, the mod registers 28 distinct types. You don't need to memorize all of them — in practice, a player only needs to know a few of the most important ones.

Other, less commonly needed types: held_item (held item scale), drops (dropped item size), projectiles (projectile size — arrows, tridents), explosions (entity explosion radius — CREEPER, END_CRYSTAL), view_bobbing (view bobbing), eye_height, hitbox_width, hitbox_height, model_width, model_height, third_person, block_reach, entity_reach.

Config

The configuration file is located at config/pehkui.json. It contains several general toggles that affect the mod's overall behavior. The rest of the file's parameters are minimum and maximum value limits for each scale type. There is no need to touch them in regular gameplay: they set safety limits for mods using the API.

Conclusion

Pehkui provides a separate toggle for each attribute, smooth transitions with a delay, and state saving between sessions. The /scale command and config are just the surface; the library's true value is revealed through mods that use its API for their mechanics. It is suitable for roleplay survival with transformation mechanics, for server minigames, and as a mandatory dependency in modpacks featuring dynamically sized bosses or racial systems.