I'm adding this page after noting that on frog e-mail lists and message boards, the subject of puffers comes up quite a bit. I've mentioned my dwarf Indian puffer, Critter, on other pages on this site. She lived with my frogs for a long time before being banished to a small tank of her own after I bought a group of platys, whose fins she mistook for dinner. It's important to note that she never tried any such thing with the frogs; in fact, she seemed to be afraid of them.
In spite of the fact that I have verifiably good experience with keeping a dwarf Indian puffer with dwarf African frogs, I've had people tell me that it is not possible. After I described my DAFs' aggression toward my puffer on one dwarf-puffer message board, some ditz tried to tell me that my frogs were actually African clawed frogs. So be warned: if you are thinking of the same arrangement, people will try to tell you that it's risky at best and stupid at worst. All I can say is, it's risky to put faith in such stupid people.
Take it from someone who has actually done it, and knows someone else who has done it: you CAN keep certain puffers with your DAFs, but you have to be careful.
For instance, many puffers are brackish water (water that has a high salt content), or saltwater (marine) fish and your DAFs cannot live in brackish water and certainly not in seawater.
Also keep in mind that most puffers become rather large. When they do, they will eat your DAFs.
From here on I'll speak strictly of the dwarf Indian puffer, with which I have direct experience. If you choose to keep a dwarf Indian puffer, you need to know several things:
The dwarf Indian puffer (commonly known as the "pea puffer;" sometimes referred to as the Malabar Puffer or simply the "dwarf puffer") is a fairly new fish in the aquarium hobby. Originally, all of these puffers were wild-caught in India. However, tank-raised dwarf Indian puffers are becoming readily available in U.S. pet stores because fish breeders have developed effective breeding techniques.
The dwarf Indian puffer (DIP 
) does not need another of its own kind to keep it company. It can live happily one to a tank. Mine currently lives in a small tank with a mirrored backing, and frequently attacks her reflection in the mirror.
I saw one site that stated that these are schooling fish. I suppose they can be -- but only if kept with no other creatures than fellow DIPs. These are NOT good community-tank fish.
If you are going to keep a DIP with DAFs, do not get more than one DIP.
The DIP has a life expectancy of about 5 years -- pretty much the same as your DAFs.
The DIP is comfortable in the same water parameters as your DAFs (pH in the neutral range; relatively high GH/KH, ideal temperature in the mid to high 70's Fahrenheit).
The DIP loves java moss as a resting/hiding place, and so do your DAFs.
DIPs are capable of harrassing and killing large fish. Always keep this in mind and have respect for their capabilities.
The female DIP tends to be less aggressive toward her tank mates than the male. Both sexes, however, can become more aggressive with age.
The female DIP is larger, rounder, and sometimes more brightly colored than the male. She is usually just under 1" long (tail included) and has black spots on a pale gold body. She has a white belly. The male is slightly smaller, thinner, sometimes almost entirely gray, with a brown stripe on the belly, running from mid-body down to the tail. It has been said that these fish cannot be reliably sexed until they are at least a 1/2" long -- or one year old! -- so refrain from buying a very tiny DIP.
If you are keeping a DIP with DAFs, get a female. Introduce her to a tank where the DAFs have been established for at least a month or two.
Give your DIP a lot of hiding places. Java moss, driftwood, and DAF-safe aquarium decorations are all good hiding places.
Observe your DIP's interactions with the frogs. My DAFs were, right from the start, extremely aggressive with my DIP, and she maintained her distance from them. However, if your DIP is more aggressive toward the frogs than they are towards her, you may have to return the DIP to the pet store.
DIPs are great for ridding tanks of an excess of snails. Ideally, they should have a snail or two in their diet every so often even if you do not have a pest-snail problem. However, if you run out of pest snails, there is no need to panic. Unlike other puffers, the DIP's teeth do not seem to over-grow when snails are absent from the diet. Some DIPs go through their whole lives never eating snails; many are maintained on flake-food diets (although, considering that these are carnivores, a strictly flake-food diet does not seem advisable in the long term and may lead to premature death).
Your DIP can share your frogs' food. However, if she becomes aggressive at mealtime and your frogs do not stand their ground, you may have to feed her separately.
A DIP cannot tell the difference between a tiny pest snail that hitched a ride on a live plant you bought, and a huge mystery snail that you deliberately bought. She will kill any snail she finds, no matter how big it is.
A DIP can eat trumpet snails, but will not eat the shell, only the contents. If you have a DIP in your aquarium, you may have trumpet snails living in the substrate and not know about it because they will never emerge with a puffer around.
DIPs do not need salt in their water. They are among the true freshwater puffers. They will not be harmed by limited amounts of salt, however, and some owners report increased health in their DIPs after the addition of small amounts of freshwater aquarium salt (not to be confused to marine-tank salt).
Don't panic if your DIP puffs. This will not hurt her or anyone else in the tank. Apparently DIPs are not poisonous unless they have eaten snails with a certain type of algae on their shells (I read this in an article written by a DIP breeder, but have not verified it). There is some indication that a DIP carcass may be poisonous, so be sure to remove a dead DIP from your tank before your frogs decide to munch on it. It's a good idea not to keep dead bodies in your fish tank, anyway, even if a dead DIP is not poisonous.
If you are going to keep a DIP in your tank, give up on the idea of keeping any other DAF-friendly fish except for otocinclus and cory catfish. Neons and guppies will be destroyed. Platys will be harrassed. Bettas (a fish that probably shouldn't be kept with DAFS, anyway), will have their fins ripped. Again, remember that these little fish can kill large fish. Basically there are very few fish that are safe with them.
But like I said, the same is not necessarily true of DAFs. If you want to keep a DIP with a crew of DAFs, I say go ahead...with caution.
