Just squishing together similar ideas along with some mixing of unrelated ideas...

* Carnivorous plants
Creeping Death (Ruins) + Zombie Needles (Splinter) + Biollante (Godzilla vs Biollante) + Swampfire (Ben10UA) + Wildvine (Ben10) + Monster Minds (Jayce and the Wheeled Warriors) + Poison Darts (Jumanji) + Audrey2 (Little Shop of Horror) + Cave Algae (The Cave) + Aragami (Blue Seed)

* Shapeshifters
Car (Super Hybrid) + Thing (The Thing 2011) + Changeling (MLP FiM) + Melona (Queen's Blade) + Clayface (Batman) + Kevin (Ben10UA) + Envy (FMA-B)

* Chimeric Mutations
Mosquitoman (Mosquitoman) + Brundlefly (The Fly) + Ginger (Ginger Snaps) + Spider (Earth vs the Spider) + Lizard (Spiderman) + Manbat (Batman) + Ninja Turtles (TMNT) + Kathoga (Relic) + Street Shark (Street Sharks) + Tillinghast (From Beyond) + Sharktopus (Sharktopus)

* Organic Machine Hybrids
Demoniac (Blassreiter) + Monster Minds (Jayce and the Wheeled Warriors) + Evos (Generator Rex) + Generators (Generator Gawl) + Boomers (Bubblegum Crisis Tokyo 2040) + The Machine (Virus) + Cybertronians (Beast Wars) + Reapers (Mass Effect)

* Swarms
Zerg (Starcraft) + Flood (Halo) + Tyranid (Warhammer 40K) + Changelings (MLP FiM) + Necromorphs (Dead Space) + Monster Minds (Jayce and the Wheeled Warriors) + Arachnids (Starship Troopers)


Fusions
* Nyaruo (Haiyoru Nyaruko-san) x Neuro (Majin Tantei Nougami Neuro) x Victor (Buso Renkin)
* Kula (King of Fighters) x Millia (Guilty Gear) x Filia (Skullgirls)
* Nyaruko (Haiyoru Nyaruko-san) x Fear (C3) x Konata (Lucky Star)
* Kuuko (Haiyoru Nyaruko-san) x Mashu (C) x Asuka (Neon Genesis Evangelion)
* Chrysalis (MLP FiM) x Kerrigan (Starcraft) x Marceline (Adventure Time)
* Saw Boss (Jayce and the Wheeled Warriors) x Ulqiorra (Bleach) x Giriko (Soul Eater)
* Flora (Jayce and the Wheeled Warriors) x Miko (Transformer Prime) x Poison Ivy (Batman)
* Pinkie (MLP FiM) x Peacock (Skullgirls) x Yuno (Mirai Nikki)
* Twilight (MLP FiM) x Arcee (Transformers Prime) x Midna (Legend of Zelda)
* Mother (Dragon Age) x Queen (AVP) x Melona (Queen's Blade)
* Tokiko (Buso Renkin) x Rukia (Bleach) x Raven (Teen Titans)

Shipping
* Rex (Generator Rex) + Miko (Transformers Prime)
* Aqua Lad (Young Justice) + Cricket (Generator Rex)
* Nyaruo (Haiyoru Nyaruko-san) + Menace (Queen's Blade)
* Kyon (The Melancholy of Haruhi Suzumiya) + Nyaruko (Haiyoru Nyaruko-san)
* Kuuko (Haiyoru Nyaruko-san) + Airi (Queen's Blade)
* Hastur (Haiyoru Nyaruko-san) + Hinata (Naruto)