Pineco

Pineco is a Bug-type Pokémon introduced in Generation II that resembles a bagworm or pinecone clinging to tree branches. It thickens its outer shell by attaching bark to its body with saliva, growing larger over time, with very old individuals becoming enormous. Known for its self-destructive defensive behavior, it bursts violently when threatened or surprised, and it eventually evolves into the steel-armored Forretress.

The Japanese name クヌギダマ (Kunugidama) combines クヌギ (kunugi), the Japanese word for the sawtooth oak tree (a kind of oak whose acorns and bark are referenced by this bagworm-like Pokémon), and ダマ/玉 (dama/tama), meaning 'ball' or 'sphere'—so it roughly means 'oak tree ball.' The English name 'Pineco' is derived from 'pine cone,' reflecting the Pokémon's resemblance to a pinecone or bagworm cocoon hanging from a tree. Both names emphasize its tree-dwelling, spherical, cocoon-like appearance.