Teeth of Cave Raxitrax

flash, defender, modular 1
costs {4} less to cast if you control 3 or more caves.
This creature gains three times X +1/+1 counters where X is the number of attacking creatures.
This creature can block any number of creatures.
If Teeth of Cave Raxitrax dies, exile it underneath a land. it is a cave in addition to its
other types.