rahi you can mutate from:
Ancient Sea Worm Rahi 
Archives Beast 
Archives Mole  
Artakha Bull  
Ash Bear 
  
Blade Burrower  
Brakas
Burnak 

Cable Crawler 
Catapult Scorpion
Cave Fish
Chute Lurker 
Colony Drone 
Crystal Climber 
Cliff Screecher

Dagger Spider 
Daikau 
Dermis Turtle 
Devourer 
Dikapi
Doom Viper

Energy Hound 
 
Fader Bull 
Fikou spider
Fireflyer 
Frost Beetle
Frost Leech 
Frostelus 
Furnace Salamander 
Fusa 

 
gadunka
Gafna  
Gate Guardian 
Ghekula
Great Temple Squid 
Gukko
Ka 

Hahnah 
Hapaka 
Hikaki 
Husi 
Hydruka 

Ice Bat 
Ice Vermin 
Infernavika 
 
Kahu 
Kane-Ra 
 
 
Kavinika 
Keras 
Kewa
Kikanalo 
Kinloka
Kirikori Nui 
Kofo-Jaga  Kraata 
Kuma-Nu 
Kuna 
 

Lava Ape 
Lava Eel  
Lava Hawk 
Lava Rat 
Lightfish 
Lightning Bug  
Lohrak 
 
Mahi  
Makika 
Makuta Fish 
Manutri
Mata Nui Cow 
Mata Nui Fishing Bird 
Metru Mantis . 
Moa  
Muaka 
Mud Crawler 

Night Creeper 
Nivawk 
Nui-Jaga  
Nui-Kopen 
Nui-Rama

Organic Rahi -Sea Squid,Giant Squid, Ancient Sea Worm Rahi,Blood Snail, Lightfish, Multiple species of birds on Mata Nui. 

Parakrekk 
Phase Dragon
Pit War Tortoise 
Pokawi  
Proto Drake  
Protocairn  
Protodites 
Protodax
 
Ranama 
Razorfish 
Razor Whale  
Rock Lion 
Rock Raptor 
Rockworm 
Ruki 

Sand Snipe 
Sand Tarakava 
Sea Spider 
Shallows Cat 
Shore Turtle
Silver Chute Spider
Sonic Creature 
Spiny Stone Ape 
Spine Slug 
Stinger Whale 
Stone Rat 
Subterranean Worm
 
Takea  
Taku  
Tarakava  
Tarakava Nui  
Troller 
Tunnel Stalker 
Tunneler 

Ussal Crab 

Vahki Hunters
Vako  
Vatuka 
Venom Flyer  
Visorak
Venom Eel 

Waikiru
Water Wraith

there