The frog's tongue is being anchored in the very front of its mouth instead of attaching it in its back. Its tongue is anchored in front in order to make hunting for prey easier because the from needs to throw its tongue to capture its food then throw the food back to its mouth.
Produce antibodies against anything with a RH positive, or different blood type. Which when the antibodies attack to different blood can cause blood clots, which could be fatal.