How to Enable the Bamboo Thrown Projectile Effect
Vanilla Minecraft does not natively support custom shapes for thrown projectiles. If your trident displays the flowery hand in first person, yet still looks like a standard spear after you throw it, you need to enable entity feature support.
Required Entity Support
To turn thrown tridents into green bamboo stalks with red bases, your client must run either OptiFine or the entity feature mods EMF and ETF together. Without one of these setups active alongside the resource pack, only the held weapon model and custom sound effects will load.
Configuring In-Game Settings
1. Open the pause menu, select Options, and click Resource Packs.
2. Move the Deltarune Flowery JARONA Resource Pack to the top of the Selected list so no other pack overrides its entity files, then click Done.
3. If you use OptiFine, navigate to Options > Video Settings > Quality and verify that Custom Entity Models is switched ON.
4. If you use EMF and ETF, open their configuration screen from your mod menu or video settings and confirm custom entity models and textures are enabled.
5. Equip a trident, hold right-click to aim, and release. When the projectile lands in grass or blocks, it will appear stuck in the surface as a custom bamboo attack.