A DwarfMod essential: allow fishing without creating a rod first, or using any material (instead it's a 'permaheld' strand of your avatar's beard. And then when actually fishing you cannot stop fishing until you have caught a fish (or been officially told that there are none in this particular compass-point of water-blocks) or been directly interupted by non-friendly fauna/etc.
(More seriously...) You ought to be able to map most of the DF menagerie to a half-way equivalent MC creature, for nominally passive wildlife you've got, what, five or six land creatures these days (it was just cow, pig and sheep when I last played) that can be duplicated and reskinned to cater for the best equivalent (camels use cow-template for commonality if milk, anything sheerable the sheep, everything gets a meat-drop anyway, potentially or even suitably enforced by whatever the Mod does that's onDeath(creature) or however it codes. Similarly, bones l, but if you want to still tie them to specific hostile mobs (undead type-clones, or antithetuc races) remod them as special bones (new requirement for the existing uses... wolf training, fertilisation and... I imagine potion-crafting, which was just set to come in shortly after I bowed out of the scene myse), where you don't want to ruin the original dependency.
All (?most?) birds can be mapped to cloned-chickens and a given reskin (plus coded behaviour/reaction changes if required) to make use of eggvand feather dropping. Not sure where MC bats will be useful in DF creature-list context (other than as various bats) but if they emulate some bird better with more minimal drop-changes to egg-and-feather providers (and suitably renamed meat) than trying to get the chicken-based alternative to become the DF aviator then try that tack instead.
I don't actually know how much flexibility the current modding process has, but it can't have less than was available back in the Beta-era I'm most familiar with (saw the introduction of Endermen, but had not yet anything that could be done with theur pearls, so they were just a minor nuisance that had to be designed around in that version or two ofnvanilla), in which there were several mods advertised that gave you lions, tigers and bears (oh my!) as part of an extended wildlife inventory from which various sole or grouped animals would be drawn upon to spawn.
There'll be various ways of doing it all. Some more faithful, some clearly more mere homage at best. And I'm sure I've heard this idea mooted on prior occasions (the loosest one was to just model the player-community on a Fortress, someone goes out fishing (with normal rod, supplied) to fulfil fisherdwarf tasks only, as others mined-only, etc, for an acceptably agreed duration) so perhaps have a look for attempts that came to sufficient fruition to act as inspiration this time round..?