IT HAPPENED, I FINALLY GOT MY SEADRAGON!!!
75th time is the charm!
So far I have played 89 stages for 3 WE and got 5 rare enemies. That is 267 WE with 5!
Today I am having a Seadragon HAYDAY!
The chance now is 5,6%.
Spent 128 tickets on 8 WE normal diff. stages and got 102 coins. (6+2+2+5+3+10+10+12+12+5+12+10+3+0+10+0).
Spent 5 tickets on 10 WE hard diff. stages and got 8 coins (8).
So far it seems that you have much better chance to get the coins by using loot tickets than actually see the rare enemy in the flesh.
There is a HUGE difference between playing the stage and loot ticketing it!