Assassin Vine
Starting Statistics: Size Medium; Speed 5 ft.; AC +2 natural armor; Attack slam (1d6); Ability Scores Str 11, Dex 11, Con 11, Int —, Wis 13, Cha 9; Special Attacks grab, constrict (1d6); Special Qualities camouflage, low-light vision, resist cold 10, electricity 10, fire 10.
4th-Level Advancement: Size Large; AC +4 natural armor; Attack slam (1d8); Ability Scores Str +8, Dex -2, Con +4; Special Attacks entangle; Special Qualities blindsight, immune electricity.
Shambling Mound
Starting statistics: Size Medium; Speed 20 ft., swim 20 ft.; AC +2 natural armor; Attack 2 slams (1d8); Ability Scores Str 10, Dex 9, Con 13, Int 7, Wis 10, Cha 9; Special Qualities darkvision 60 ft., low-light vision, resist fire 10, immune electricity, electric fortitude.
4th-Level Advancement: Size Large; AC +4 natural armor; Attack 2 slams (2d6); Ability Scores Str +8, Dex -2, Con +4; Special Attacks constrict (2d6), grab.
Treant
Starting Statistics: Size Medium; Speed 30 ft.; AC +2 natural armor; Attack 2 slams (1d6); Ability Scores Str 15, Dex 6, Con 15, Int 12, Wis 16, Cha 13; Special Qualities low-light vision, DR 5/slashing, treespeech; Weaknesses vulnerability to fire; Skills +16 Stealth in forests.
7th-Level Advancement: Size Large; AC +4 natural armor; Attack 2 slams (1d8); Ability Scores Str +8, Dex -2, Con +4; Special Qualities double damage against objects, DR 10/slashing.
Vegepygmy
Starting Statistics: Size Small; Speed 30 ft.; AC +1 natural armor; Attack 2 claws (1d4); Ability Scores Str 11, Dex 14, Con 12, Int 8*, Wis 11, Cha 11; Special Qualities darkvision 60 ft., low-light vision, DR 5/slashing or bludgeoning, electricity resist 10; Skills +4 Stealth (+12 in vegetation).
7th-Level Advancement: Ability Scores Str +2, Dex +2; Special Attacks russet mold spores (as vegepygmy chieftain); Special Qualities Immune electricity.