Finger chaser for 20L??

[MANGCH1]

is there a super aggressive fish that will basically chase your finger and not tolerate tankmates that can live in a 20 gallon long for life?

 

[Nabbig2]

Convicts

 

[MANGCH1]

loll their pretty aggressive. but i wouldnt call them "finger chasers" like a flowerhorn or red devil.

 

[Nabbig2]

But they can live in a 20L for life, which is what you asked for.

 

[bitteraspects]

no. there isnt

 

[Cichlaholics Anonymous]

a big male convict will be pretty close, the size of the tank obviously limits what you can do.

 

[fishy12]

exodon a couple of them like 5 or 6

 

[TTTT]

10 exodons would be better, 5 would kill each other.

I think a big, nuchal humped male convict is your best option.

 

[boldtogether]

Male Convict, no plants, -some- sand or small gravel.

 

[bitteraspects]

Exodons should be kept in a group of 10. Which would work in that tank, but will not give the OP their desired effect.
Convicts tend to only show that type of aggression when spawning, but even then, its not quite the same effect.

as mentioned above, the tanksize greatly limits your options. And while you can get some pretty cool and semi aggressive fish in a 20g, you'll be hard pressed to find the "mini RD/FH" you're looking for.
A lot of the time, its more dependent on the individual fish more so than the species. I've seen Bettas that were little "finger chasers" and others that would mostly just float in place.

Check out the mini monsters thread for some ideas for your tank. Somethings bound to strike your fancy.