Bat Themed Monsters?

[Kotenkiri]

so my PC has just gone through the Hidden Shrine of Tamochan and thus made Zotzilaha an enemy. The book suggest sending vampires or giants bats as Zotzilaha has a bat and god of dead thing go.

My PCs (3x level 7's and 1x level 6) are able to kill the undead without much difficulty so wondering I could work on the Bat theme angle but lacking in bat monsters.

[Trask]

Reskinning is your friend. Could easily reskin a wyvern as a gigantic bat abomination, remove stinger in favor of a vampiric blood drain attack

[Requilac]

so my PC has just gone through the Hidden Shrine of Tamochan and thus made Zotzilaha an enemy. The book suggest sending vampires or giants bats as Zotzilaha has a bat and god of dead thing go.

My PCs (3x level 7's and 1x level 6) are able to kill the undead without much difficulty so wondering I could work on the Bat theme angle but lacking in bat monsters.

If you are acceptable with homebrewed monsters, there is a lot to work with here. You could make or find "dire giant bats" which are scaled to the party's level. Upscaled stirges of course are also a fun option. Giant dire mosquitos, while not directly related to bats, may also make some thematic sense. And if you are looking for something a little more menacing, you could always create a sort of Night Gaunt (https://www.d20pfsrd.com/bestiary/monster-listings/monstrous-humanoids/nightgaunt/). They were originally from some of Lovecraft's more Dunsayan, less horrific, tales but Pathfinder statted them up and made them a monster canonical in the core rules. Making a conversion of the ones from PF to D&D 5e should be pretty easy.