Unity move vertex shader thing

Blob.shader

Shader "Custom/Blob" {
	Properties {
		_Color ("Color", Color) = (1,1,1,1)
		_MainTex ("Albedo (RGB)", 2D) = "white" {}
		_PushTex ("Thing", 2D) = "white" {}
		_Push ("Push", Range(-1,1)) = 0.0
	}
	SubShader {
		Tags { "RenderType"="Opaque" }
		LOD 200

		CGPROGRAM
		// Physically based Standard lighting model, and enable shadows on all light types
		#pragma surface surf Lambert vertex:vert

		// Use shader model 3.0 target, to get nicer looking lighting
		#pragma target 3.0

		sampler2D _MainTex;
		sampler2D _PushTex;

		struct appdata {
			float4 vertex : POSITION;
            float4 texcoord : TEXCOORD0;
			float3 normal : NORMAL;
		};

		struct Input {
			float2 uv_MainTex;
		};

		fixed4 _Color;
		float _Push;

		void vert (inout appdata_full v) {
			float pushy = tex2Dlod (_PushTex, v.texcoord + float4(0,_Time.y,0,0)).r;
			v.vertex.xyz += v.normal * _Push * pushy;
		}

		void surf (Input IN, inout SurfaceOutput o) {
			fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
			o.Albedo = c.rgb;
		}
		ENDCG
	}
	FallBack "Diffuse"
}