1. Gulper catfish. Especially the schadenfreude gulpers that are kept with other, far more expensive fish and invariably live up to their name.
2. Some kind of Pseudacanthicus, maybe L114 or L600
3. Brachyrhamdia imitator
4. Boraras maculatus
5. (bonus: currently kept fish) L106 Hemiancistrus guahiborum. Good sized, robust, and bold enough to get its odontodes out and ram your hand if you get too close while cleaning. Cool little pleco.
2. Some kind of Pseudacanthicus, maybe L114 or L600
3. Brachyrhamdia imitator
4. Boraras maculatus
5. (bonus: currently kept fish) L106 Hemiancistrus guahiborum. Good sized, robust, and bold enough to get its odontodes out and ram your hand if you get too close while cleaning. Cool little pleco.