Wow in a 55 gallon tank heck yeah they will all kill each other. Porc puffers can grow to about 2 feet best suited to at least a 150 if not bigger really. No joke you have to take a real look at your stock list. that sounds like it should be in a 300 gallon tank. Not trying to be rude btw. some years ago when i started this hobby a pet store sold me a empire angle, sweet lips and a clown fish all in one day to put in my thirty gallon tank that had only been set up for 2 days. research everything you buy. You will save your self a lot of money in the long run...CLOWN TRIGGERMinimum Tank Size: 125 gallons
Care Level: Easy
Temperament: Aggressive
Reef Compatible: No
Water Conditions: 72-78° F, dKH 8-12, pH 8.1-8.4, sg 1.020-1.025
Max. Size: 1' 8"
Color Form: Black, Blue, Green, Orange, White, Yellow
Diet: Carnivore
Compatibility: View Chart
Origin: Indonesia, Sumatra
Family: Balistidae
Cream Angel
Minimum Tank Size: 70 gallons
Care Level: Easy
Temperament: Aggressive
Reef Compatible: With Caution
Water Conditions: 72-78° F, dKH 8-12, pH 8.1-8.4, sg 1.020-1.025
Max. Size: 8"
Color Form: Black, Yellow
Diet: Omnivore
Compatibility: View Chart
Origin: Sri Lanka
Family: Pomacanthidae
Porc puffer
Minimum Tank Size: 90 gallons
Care Level: Moderate
Temperament: Semi-aggressive
Reef Compatible: No
Water Conditions: 72-78° F, dKH 8-12, pH 8.1-8.4, sg 1.020-1.025
Max. Size: 1'
Color Form: Black, Tan, Yellow
Diet: Omnivore
Compatibility: View Chart
Origin: Caribbean
Family: Diodontidae
And IREALLYFeel That even those are a little small on the tank Req