Tomb of Annihilation is surely one of the best adventures for D&D 5e so far.
My love for designing and reskinning monsters (and NPCs) drove me to create three new ones for my campaign in Chult: Batiri Warlock, Pterafolk Alpha and Shadow Stalker.
The weirdest thing is that one of them, the Shadow Stalker, was never encountered by the players, because the storyline evolved in a different way than what I'd originally planned.
Statblocks are there
BATIRI WARLOCK
The Batiri Warlock is a special member of the tribe who has been blessed by a pact with some ancient spirit that dwells in the forest. Alternatively, its patron can be one of the surviving Barae of Mezro, or some extraplanar creature or SzassTam too.
PTERAFOLK ALPHA
A Pterafolk Alpha is the leader of its flock. Approximately, 1 in a 10 pterafolks is a Pterafolk Alpha. It's bigger and stronger than its counterparts.
SHADOW STALKER
A Shadow Stalker is a human that still follows the teachings of Eshowdow.
Bye.
The DM