Here is the only OSR Scarecrow you need. This is the Scarecrow from The Witch.
(Yeah I am a little late on the snark here, term start and I have a conference to go to this week.)
AC: 9 
Hit Dice: 3d8* (14 hp)
No. of Attacks: 2 Limbs
Special: Paralyzing Gaze, Triple Damage from Fire based attacks
No. Appearing: 1 (always in lair)
Saves As: Fighter 3
Scarecrows are basic guardians similar to golems, but not nearly as powerful. Like typical scarecrows, their bodies are made of straw and cloth. The stumble about their assigned area poorly and attack most anything that wanders through it. Some Scarecrow Guardians are bound to a post. A Scarecrow can use their paralyzing gaze to imprison any trespassers (save vs. Paralysis, fail means victim remains rooted to the spot).
Scarecrows are assigned to protect a particular area. They never leave the area, even when chasing an intruder. They will attack anything, humanoid or animal like in appearance that walks into its territory unless otherwise instructed by their creator.
A scarecrow is immune to mind-influencing effects, poison, disease and similar effects. They are not subject to critical hits, subdual damage, ability damage, energy drain or death from massive damage.
Fire Vulnerability: Because of their straw bodies, Scarecrows are extremely vulnerable to attacks from fire. They take triple damage from all fire attacks.
In addition, a scarecrow guardian will catch fire easily after any attack that would normally ignite mundane items. A scarecrow on fire receives 2d6 damage each round (do not double this damage)
All content is designated as Open for the Open Gaming License.
Art is from the Public Domain
Section 15 OGL Copyright Notice
The Witch, Copyright ©2012, Timothy S. Brannan
"Scarecrow" Copyright ©2014, Timothy S. Brannan