The flag weed makes you run faster. Same with the flag zombie
The Flag Zombie and Flag Weed both impart a small defensive buff when you are within a particular range of them- when within range you'll see a small glowing near the bottom of the affected characters. In addition the Flag bearing versions of both the Weed and Browncoat are programmed to follow Players around.
It occurs to me that you could conceivably spawn a little mob of them and have them follow you around and see how that affects game dynamics but I haven't tried that yet myself.
I like planting lots of medic weeds and heal zombies. I've gotten the heal master boast a number of times when playing, for example, imp! If I'm tanking it to the base as all star, I'll pop one out to follow me, but if your health is full, they just wander off in search of someone else to heal.
