i have a columbian(gold)tegu that was pure evil, in fact his name is diablo(anyone who doesnt kno, thats devil in spanish.)but after some regular interaction and tons of bites he has finally calmed down. actually, at times i would just let him bite me and after he realized that i didnt care and it wasnt getting him anywhere, he stopped. now he lets me take him out of his cage and hold him and i can sit him on my lap and he will just sit there. he will huff and hiss a little bit at first but he calms down after a minute. in all honesty there are very few animals i will say are ALWAYS nasty. if you dedicate enough time and patience to almost any animal they will tame down usually. except for the knights (cuban knight anoles, anolis equestris) they are one thing i have given up on taming... its not possible
if you work with them a bit, and feed outside of there cage i would say there is a fair chance they should tame down, you might want to invest in a nice pair of gloves though. good luck.
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"it is better to remain silent and be thought a fool than to open your mouth and remove all doubt"
1.0.0 bearded dragon
1.1.0 green iguana
0.0.1 columbian tegu(for sale)
1.1.0 knight anole
0.1.0 green anole
0.1.0 asian longtail grass lizard
1.1.0 golden gecko
1.0.0 ball python
0.0.5 oriental firebellied toad
0.0.1 green treefrog
0.0.1 barking treefrog
0.0.1 cuban masked treefrog
0.0.1 gray treefrog
0.1.0 gulf hammock rat snake
0.1.0 eastern kingsnake
0.1.0 siberian husky
1.1.0 ratties
0.1.0 hedgie