"Experiment" can mean/refer to several things, and therefore is an ambiguous term. Use more specific tags instead, such as:

Characters

Lilo & Stitch

Canon characters

• experiment_624, better known as Angel. (Tagged as angel_(lilo_and_stitch).)
• experiment_625, better known as Reuben. (Tagged as reuben_(lilo_and_stitch).)
• experiment_626, better known as Stitch. (Tagged as stitch_(lilo_and_stitch).)
• experiment_627

See also the many other Lilo & Stitch experiments on the wiki page for their overall "species" listed below.

Fan characters (containing the word "experiment")

• chance_(experiment)
• chibi_(experiment)
• lilo_pelekai_(experiment) – Canon character reinterpreted as a genetic experiment.
• experiment_666_(metallicumbrage)
• experiment_723_(aotsukifur24)
• naomi_(experiment_631)
• nova_(experiment)
• sdmemory's_experiment
• shadow_(fan_experiment)
• slippy_(fan_experiment)
• stream_(experiment_762)

Other

• experiment_18 – Pokémon fan character.
• experiment_47_(blackdragon4444)
• experiment_131_(monsterinsideme)

Copyright

• experiment_101 – Developer of Biomutant.
• experimentation_(series)
• russian_sleep_experiment
• the_spoony_experiment

Objects/Other

• experiment_pod – Also Lilo & Stitch-related.
• scientific_experiment
• what_has_science_done for far out weird scientific experiment results, or things that at least look like such.
• straight_to_gay

Species

• experiment_(lilo_and_stitch)

Artists

• escapedexperiment_(artist)
• experimentalnsfw
• pinseltheexperiment