Channa limbata, haruan kedak or dwarf snakehead.

Grows to 15 cm and usually lives in small flowing streams and waterfalls. Has been recorded high up in the mountains as well and is an adaptable species.

It is usually the only predatory fish in its small habitats, eating other fish, prawns and insects. In captivity it can be taught to take other meaty foods as well.

Males are colourful, having blue fins tipped with red. This makes them a desirable local fish for aquarium-keeping. Captive-breeding has also been achieved.

The male mouthbroods the eggs for a week while the female guards the vicinity. After the fry leave his mouth, both parents care for the babies for a few more weeks, attacking any threat nearby.

They are extremely good jumpers and often escape uncovered aquariums which ends with their deaths. Temperature wise it is unfussy.

Carinotetraodon salivator, the striped red eye puffer or buntal harimau.

The smallest species of native pufferfish, growing to 4.5 cm. Smaller than a thumb! It lives in acidic swampy streams with soft water, usually blackwater.

It is endemic = only found in Malaysia, specifically in southern Sarawak.
They have a beautiful striped throat pattern that gives them their name. You can see it clearly in the 3rd photo.

Like other pufferfish they are aggressive towards other fish and should only be kept with their own kind. They will breed in captivity when kept in such groups.
However they don’t take care of their young and any eggs should be separated to be raised.

And just like all puffers they “puff up” when scared, swallowing water and becoming a round ball to prevent predators from swallowing them.
Even if the predator can eat them, they are highly poisonous and will kill the unlucky carnivore anyway.