Quote from VitusW >>

As Lyra dashes to her destination her first blast sends the longbow-wielder off his mount, splatting him on the ground. The second, now impeded by the giant lizard, however closely misses its mark.

[[ Correct on no cover from the location she ended for making the attacks. Though with the blasts getting resolved sequentially the 1/2 cover from the interposing creature on the second blast was created after he was dismounted. (Technically in this case would also be disadvantage from him being prone but as the rolled roll already misses there, no point rolling the second IMO.) ]]

As he lays prone on the ground he snarls out, now in Common, "I'll gut you like a dog!" Though he's clearly trying to be intimidating, it's clear from his demeanor that he fears for his life.

The lizardmen seem annoyed by Zephyr's glib remarks about if the javelins were meant for him. As the webbing shoots out they do their best to avoid it.

DEX Saves vs DC 16
Tree: 3
Rider 1: 16
Giant Lizard 1: 8

Tree gets prone and restrained all at once in a delightful situation. While Rider 1 avoid the sticky webs his mount gets a bit flustered.

Initiative
Rider 1 (mount is restrained, Rider 2, Tree (20 damage, prone, restrained)
Fenric (concentrating on hunter's mark, Lyra (concentrating on expeditious retreat), Zephyr (z = +20, concentrating on web) <----------- currently up
Longbow (56 damage. hunter's mark), Tough Lizard, Giant Lizard 2
YugJug (sanctuary, 12thp)

Fenric hears Zephyr's request and turns his gaze to the lizard in question. "Your wish is my command!" he cries out, before sending an arrow doused in thorn magic barreling towards his target. As he goes to release another arrow, hand slips and the arrow flies straight into the side of a tree with a resounding thunk.

Movement: 5' NE, 20' NE, 10' NE. I think this gives me the best shot at the fleeing lizard.

Bonus Action: Fenric will drop concentration on Hunter's Mark to cast Hail of Thorns at second level (hoping to kill the lizard before he can escape).

Action: Fenric will shoot at the fleeing lizard.

Attack 1: To Hit: 22 Damage: 28 or 20 (13 + 15 Hail of Thorns, DEX save DC 14 to take half damage from Hail of Thorns)

Attack 2: To Hit: Nat 1 (10) Damage: 10

[[
For Fenric's positioning, I'm guessing the repeated NE there was a typo. I do see easily a way where it only has 1/2 cover from the giant lizard. 5SE, 5E, 15SE 10 E.

As a reminder, since the lizardman is prone (realized I forgot to include that in my statuses update; whoops) Fenric's attacks have disadvantage. (right now that 13,1 would be a nat-1 on the first attack.)

I'll also note, since Lyra's second attack hits now, that he is at 63 damage and looking to be on his last legs.
]]

[[ Now that I realize I misread what you meant (whoopsie on my part) ]]

Fenric's first arrow strikes true, causing a hail of thorns to burst out.

Giant Lizard 1 DEX Save: 21
Rider 1 DEX Save: 8

Forgot to do disadvantage on DEX Save for restrained lizard 12

Both the rider and lizard take the full brunt of Fenric's spell. The rider explodes in a hail of thorn from Fenric's arrow (taking him as the primary target) with the mount being grievously wounded.

[[ For sake of simplicity will assume Tree was the second target after Rider 1 died. (adv from restrained and disadv from prone cancel out to keep the nat-1.) ]]

Longbow dashes to get back up and on his mount once more, driving it to flee to the East.

Taking a cue, the Tough Lizard follows suit.

Giant Lizard 2 continues mozying about.

YugJug heads towards Lyra, ready to round about from the South and over.

Rider 1's Mount (Giant Lizard 1) tries to free itself from Zephyr's webbing. If it succeeds it starts running East, leaping where it can.

STR vs DC 16 14

Tree also tries to free himself. 14, and crawl through and out of the web.
Second DEX Save: 20

[[ Both remain trapped by the web. ]]

Initiative
Giant Lizard 1 (15 damage, restrained), Rider 2, Tree (20 damage, prone, restrained)
Fenric, Lyra (concentrating on expeditious retreat), Zephyr (z = +20, concentrating on web) <----------- currently up
Longbow (63 damage), Tough Lizard, Giant Lizard 2
YugJug (sanctuary, 12thp)

Lyra lopes after the fleeing Mr. Longbow, south and east around the overgrown area, determined not to allow him an easy escape.  As she vanishes in a black-tinged silvery mist and reappears, cutting the corner, her mellifluous voice continues to ring out through the woodlands, still in Draconic:

"Truly, I commend you on the breathtaking alacrity with which you are so bravely running away, after having first laid an ambush to slay innocents."

Bonus Action and Movement:  35' movement and Misty Step without a spell slot using Fey Touched feat:
5' S, 10' SE, Misty Step 30' SE cutting the corner past the overgrown area, then continuing 20' E, Attacking at the end of all that.

Action:  Lyra attempts, with less success, to target Mr. Longbow with two more onyx-hued Eldritch Blast beams (still well within 120' range):

Eldritch Blast beam 1 to hit Mr. Longbow:  8 (Natural 1)

Eldritch Blast beam 2 to hit Mr. Longbow:  13
Eldritch Blast beam 2 damage (guessing it misses, but just in case):  10 (force)

(Lyra has reaction spells available and may use them.)

Lyra is able to swiftly catch up in range to the longbow-wielding lizardman. Although her luck with aim is not as good as before. He swings around in his saddle, arrow knocked, as the eldritch blasts swarm around him. "And I admire your alacrity in having the aim of a drunkard!" he quips back.

Initiative
Giant Lizard 1 (15 damage, restrained), Rider 2, Tree (20 damage, prone, restrained)
Fenric, Lyra (concentrating on expeditious retreat), Zephyr (z = +20, concentrating on web) <----------- currently up (please wait for clarification from Ropland)
Longbow (63 damage), Tough Lizard, Giant Lizard 2
YugJug (sanctuary, 12thp)

[[ updates with Ropland's confirmation ]]

Rider 1, no longer dead, instead throws javelins at Ropland (his best target) when his mount can't get free despite his urging.

Javelin @ Ropland //+2 AC from half-cover
Attack: 8 Damage: 5

Javelin @ Ropland //+2 AC from half-cover
Attack: 10 Damage: Unable to parse dice roll.

Giant Lizard 2, its rider dead and itself wounded, flees into the forest dashing away.

(if you need a reference on Longbow Lizardman or Tough Lizard use prior screenshot for their positioning)

EDIT: just realized I referred to Panflute's mount as Giant Lizard 2 before. And now I'm in a naming scheme so Giant Lizard 2 in scene is Panflute's (going to fix that going forward) and Giant Liard 2 that's got 15 damage and is off-screen is the one Rider 2 was riding.

Initiative
Giant Lizard 2 (15 damage), Rider 1 (mount is restrained), Tree (20 damage, prone, restrained)
Fenric, Lyra (concentrating on expeditious retreat), Zephyr (z = +20, concentrating on web) <----------- currently up
Longbow (63 damage), Tough Lizard, Giant Lizard 2
YugJug (sanctuary, 12thp)