Ankylolisk series: Would be an armored Chromalisk-like ankylosaur. Attacks using their tail. Basically a Beast equivalent to the Lumber. Has the ability to inflict Stun.
Rhinoceros series: A rhino. Uses a charge as an attack, with some stomping involved. Unstoppable while charging. Has stunning capabilities.
Gremlin Biker series: A gremlin Thwacker riding a motorcycle with a status-reflecting Gun Puppy on it. Would chase you until the bike has blown up. Not only the attacks of Gremlin Thwacker and Gun Puppy, but he would try to ram you with the piercing/stunning spikes on the bike.
Scorpion series: A scorpion. A beast mini with a bigger form that can be ridden by Gremlin Mortafires for a great challenge. Attacks with claws and a stinger that always can inflict Poison.
[Edit below]
Cheetah series: A cheetah. Dashes to try and coughcougheatyoucoughcough.
[BOSS ALERT] Roarmulus Rex Twins: A T-Rex version of the Roarmulus Twins battle.
[LEVEL ALERT] Savannah: Home to the Cheetah series, Ankylolisk series, and Rhinoceros series.
[LEVEL ALERT] Snororan Desert: home to Statusless, Freeze, Sleep, and Poison Beasts, with Slimes mostly being Sleep, and Beasts being mostly Sleep and Poison. Home to a miniboss, Team Desert.
[MINI ALERT] Foxer Mega-series: Consists of Fennec (Statusless, Sleep(RARE ALERT), Poison)(Snororan Desert), Red (Statusless, Fire, Sleep(RARE ALERT), Shock, Poison)(Wolver Den, Wild Path, Chittering Burrows, Snororan Desert (OASIS ALERT), Candlestick Keep), Grey (RARE ALERT)(Stun, Freeze, Sleep(SUPER RARE ALERT), Poison)(Wolver Den, Wild Path, Slimeway, Scarlet Fortress, Candlestick Keep, Firestorm Citadel, Treasure Vault (COMMON ALERT), Gardens/Ruins Lockdown (COMMON ALERT), Chittering Burrows, Snororan Desert (OASIS ALERT)), and Arctic (Statusless, Sleep (UNCOMMON ALERT), Poison, Freeze)(Freeze levels)
[MINIBOSS ALERT] Team Desert: Fennec Foxer Poppy, who was once a Vanguard, according to Clockwork News Network, Hank the Grey Wolver (could be an Ash Tail if needed), and Bill the Vulturer make a team.
(Cutscene)
Poppy: Prepare for trouble!
Bill: And make it triple!
Hank: To protect the world from devastation!
Bill and Poppy: To separate all persons from Poppy's former nation!
Poppy: To denounce the evils of truth and love!
Bill and Hank: To extend our reach to the Clockworks above!
Poppy: Poppy!
Bill: Bill!
Hank: Hank!
Poppy: Team Desert!
Team Desert: Blast off at the speed of light! Surrender now or prepare to fight!
Poppy: Poppy! That's right!
(Three blasts are heard if the volume is on)
[PLAYERNAME]: Poppy, didn't you announce yourself before Bill did?
Poppy: I KNOW THAT! Get the Team Rocket pun, though?
[PLAYERNAME]: Yes./No.
Poppy: All right. Now surrender now or prepare to fight./HOW DARE YOU! Now prepare to FIGHT!
[PLAYERNAME](If [PLAYERNAME] said yes, than this will pop up): (surrender, thus ending conversation, and everyone in the party is blasted of the resetting party button)/Enough talk. Let's fight. KAPOOEY! (punch Poppy, thus ending conversation and starting the fight)
(If [PLAYERNAME] said no, than the fight begins with Poppy punching a random [PLAYERNAME] before the party can do any further action)
The fight is oriented at alternating between Bill/Hank, and Poppy herself. The second-to-last stage (1(B/H)->2(P)->3->4(P))has all three, but is a Bill/Hank focused stage.
Vulturer series: The flying inhabitants of Beast levels (except for healers). Appears in Beast levels ONLY.

And a big dino boss :D Maybe gremlins could construct a mecha t-rex gun puppy and release it causing havoc and mass chaos that we knights must stop mwehehe.

I think adding treants in the game would be awesome!