Enderwolven

Enderwolven (sin. Enderwolf) are strange creatures almost indigenous to The End and nearby areas (including Terra. They can grow up to the length of a semi truck (and occasionally to the size of whole moons and planets), with armor-plated scales underneath dark fur. They are all unbelievably intelligent. It has unbelievable camouflage abilities, and has three to four compound-slit eyes (basically half-fly and half-snake) on each side of its head. Each one of its razor-sharp teeth is the length of Slenderman's arm (at regular length, with the moon-size having average-crater-size, and the planet-size having very-large-asteroid-size). It can speak many languages, and its roar can cause paralysis, shockwaves, and (in the case of the larger ones) total lunar, planetary, solar and/or systemic devastation. It has up to four tails (but three on average), each scorpionic in design, with each causing a different ailment. The pool for ailments is: Death, paralysis, petrification, poisoning, crystallisation, vampiric draining, hallucination, corruption, Wither Sickness, transformation, mutation, cancer, Ebola, depression, "Cthulhu Fthagn" (makes them worship the Lord Cthulhu), possession, and immortality (yes, this is an ailment. Just ask Silas).
The residents of The End have made cures, remedies and purifiers for all the above ailments, and Ender himself is fluent in creating these remedies and using the Cure Power (a special needle machine). He is the only person in the Master League to know how to do so (apart from Endor, who can do more or less anything. He doesn't even require a needle). 
As cubs, they are very loyal to anyone who befriends them, and are born from the last beat of a dying Enderwolf's heart. They are also able to get along well with tigers, bears, dogs, other big cats (like lions), wolves, Ender-Folk AND humans (sometimes).