This is a paid asset, but now you can download Bionic structures Free.
Detail this asset from Unity Store: Original Link
Bionic structures v1.0
Here you can find a lot (91) of bionc objects.
All main textures is 4096×4096 and include full PBR set.
Triangles counts:
BiomassSmall_1_1 – 1290 triangles
BiomassSmall_1_2 – 546 triangles
BiomassSmall_1_3 – 1166 triangles
BiomassSmall_2_1 – 416 triangles
BiomassSmall_2_2 – 428 triangles
BiomassSmall_2_3 – 628 triangles
BiomassSmall_3_1 – 517 triangles
BiomassSmall_3_2 – 494 triangles
BiomassSmall_3_3 – 613 triangles
BiomassSmall_3_4 – 449 triangles
BiomassSmall_3_5 – 323 triangles
BiomassSmall_4_1 – 872 triangles
BiomassSmall_4_2 – 376 triangles
BiomassSmall_4_3 – 418 triangles
BiomassSmall_4_3 (1) – 418 triangles
BiomassSmall_4_4 – 574 triangles
BiomassSmall_4_5 – 260 triangles
BioStructure1_1 – 1116 triangles
BioStructure1_2 – 1576 triangles
BioStructure1_3 – 1938 triangles
BioStructure10_1 – 3430 triangles
BioStructure10_2 – 3744 triangles
BioStructure2_1 – 1334 triangles
BioStructure2_2 – 676 triangles
BioStructure2_3 – 1656 triangles
BioStructure2_4 – 354 triangles
BioStructure2_5 – 470 triangles
BioStructure2_5 (1) – 470 triangles
BioStructure2_6 – 414 triangles
BioStructure3_1 – 3410 triangles
BioStructure3_2 – 1474 triangles
BioStructure3_3 – 884 triangles
BioStructure4_1 – 894 triangles
BioStructure4_2 – 492 triangles
BioStructure5_1 – 640 triangles
BioStructure5_2 – 602 triangles
BioStructure5_3 – 526 triangles
BioStructure6_1 – 3156 triangles
BioStructure6_2 – 3244 triangles
BioStructure6_3 – 3780 triangles
BioStructure7_1 – 1012 triangles
BioStructure7_2 – 1980 triangles
BioStructure7_3 – 1468 triangles
BioStructure8 – 1826 triangles
BioStructure9_1 – 2244 triangles
BioStructure9_2 – 1648 triangles
BioStructure9_3 – 2276 triangles